CHU CHEUNG CHEUNG AND ANOTHER v. THE INCORPORATED OWNERS OF PROVIDENT CENTRE No 21-53 WHARF ROAD, NORTH POINT, HONG KONG AND OTHERS

DCCJ 244/2021

[2024] HKDC 1899

IN THE DISTRICT COURT OF THE

HONG KONG SPECIAL ADMINISTRATIVE REGION

CIVIL ACTION NO 244 OF 2021

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BETWEEN

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JUDGMENT

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A. Overview

1.  The disputes relating to this water leakage case have a chequered history that dated back to 2011 (which was 13 years ago).

2.  The Plaintiffs are the registered owners of Flat D, 25/F, Block 12A, Provident Centre, Nos 21-53 Wharf Road, North Point, Hong Kong (hereinafter “Flat 25D”).

3.  The 1^st Defendant is the incorporated owners of Provident Centre.

4.  The 2^nd Defendant is the manager engaged by the 1^st Defendant, and it is responsible for, inter alios, managing the common parts of Provident Centre on a day-to-day basis.

5.  The 4^th Defendant was a contractor engaged by the 1^st and/or 2^nd Defendants to carry out, inter alios, reparation works on the roof of Block 12A of Provident Centre.

6.  Throughout the years, various contractors were involved in carrying out waterproofing works on the roof above Flat 25D[1]. Despite these repeated waterproofing works, the water leakage problem persisted and recurred.

7.  By now, the 1^st Defendant has provided an undertaking[2] that it would implement the recommendations set out in the survey report dated 21^st September 2022 (hereinafter the “Global Generation’s Report”)[3] prepared by Global Generation Consulting Engineers Ltd (“Global Generation”).

8.  Upon the 1^st Defendant’s undertaking, the Plaintiffs were granted leave to withdraw its claims for mandatory injunction against the Defendants[4].

9.  The only outstanding substantive matter is the Plaintiffs’ claims for damages.

10.  In the present trial:-

(1) the Plaintiffs are represented by Mr Vincent Li;

(2) the 1^st and 2^nd Defendants are represented by Mr Wong Cho Lik; and

(3) the 4^th Defendant is represented by Mr Stephen Siu.

B. Material Background

B1. Provident Centre, the Common Areas and the 25D Unit

11.  The Provident Centre is an estate development that comprises 17 residential buildings. The individual units there have been occupied since around 1982.

12.  The Plaintiffs are a married couple. Whilst the 1^st Plaintiff[5] is a retired secondary school teacher, the 2^nd Plaintiff[6] is a retired nurse.

13.  On 4^th November 1986, the Plaintiffs became the registered owners of Flat 25D in Block 12A. They purchased Flat 25D for investment purposes. At all material times, the Plaintiffs rented out Flat 25D for rental income[7].

14.  It is not in dispute that:-

(1) The roof on Block 12A (the “Roof”) is immediately above Flat 25D, and it is a common part of Provident Centre.

(2) There are, inter alios, water tank houses (the “Water Tank Houses”), a pump house and a staircase house (the “Staircase House”) on the Roof. They are also common parts of Provident Centre.

B2. Events leading to DCCJ 2246/2014

15.  As early as June 2011, the Plaintiffs made a complaint about water seepage in Flat 25D. From 2012 to 2013, Fai Hung Construction Co and SKY Waterproofer & Contractor Co Ltd (hereinafter “SKY”) were engaged by the 1^st and 2^nd Defendants, and they made no less than 8 attempts to repair the waterproofing membrane on the Roof[8]. However, the water seepage persisted.

16.  As a result of the water seepage, the Plaintiffs’ tenant[9] made repeated complaints. He eventually ended the tenancy on 2^nd July 2013[10].

17.  The 1^st Plaintiff said that he engaged workers to repair and renovate Flat 25D on numerous occasions. Believing that the water seepage problem would soon be resolved, on 27^th January 2014 the Plaintiffs leased Flat 25D to a new tenant named Hung Ka Shun (洪嘉信) (hereinafter “Mr Hung”)[11]. However, the water seepage problem was not resolved[12].

18.  Since the water seepage continued, in June 2014 the Plaintiffs commenced DCCJ 2246/2014 against the 1^st and 2^nd Defendants as well as SKY.

19.  Pursuant to the consent order made by Master David Chan on 2^nd November 2017, DCCJ 2246/2014 was settled. Whilst the 1^st Defendant agreed to pay the Plaintiffs a settlement sum of HK$300,000, the 1^st Defendant also undertook to carry out waterproofing work on the Roof by 15^th March 2018.

20.  The 1^st Defendant says that it agreed to the aforesaid settlement on the basis that no liability was admitted and that it had fulfilled the undertaking under the said consent order dated 2^nd November 2017[13].

B3. Works done pursuant to the 2016 Tender and December 2016 Engagement Letter

21.  It appears that before the parties settled DCCJ 2246/2014, in October 2016, the 1^st Defendant had already issued a tender in respect of the reparation works on the Roof (the “2016 Tender”).

22.  The 1^st Defendant received two quotations, one of which came from the 4^th Defendant.

23.  Pursuant to the engagement letter dated 21^st December 2016 (the “December 2016 Engagement Letter”)[14], the 4^th Defendant agreed to carry out, and did carry out, re-roofing works in respect of the floor on the Roof and the “parapet wall” on the Roof[15]. When the 4^th Defendant’s witness, namely Mr Chiu Kwan Fung (趙均峰) (“Mr Chiu”) testified, he explained that “parapet wall” meant the L-shape junctures (up to 500mm vertically) between the floor on the Roof and the walls of the structures erected on the Roof. The L-shape junctures are colloquially referred to as “腳線”. Mr Chiu’s evidence is consistent with the contemporaneous documents (including the December 2016 Engagement Letter and the documents in respect of the 2016 Tender) and not in dispute.

24.  Mr Stephen Siu (for the 4^th Defendant) emphasizes that whilst the 2016 Tender consisted of 12 items of works, the 4^th Defendant was only engaged to carry out 3 items of works pursuant to the December 2016 Engagement Letter. In particular, the 4^th Defendant was not engaged to carry out any re-surfacing or reparation work in relation to the Water Tank Houses, which contain the flush water tank, the freshwater tank and the fire services water tank of Block 12A. The implications will be addressed hereinbelow.

25.  According to the 4^th Defendant[16]:-

(1) In around late January or early February 2018, he duly completed the re-roofing work, including the replacement of the waterproof membrane, on the entire floor of the Roof.

(2) A fluorescent dye test was conducted during the period from 3^rd to 5^th February 2018, and inspections were carried out on 9^th February 2018 and 12^th, 20^th and 21^st March 2018. No fluorescent dye was noticeable on the ceiling of Flat 25D.

26.  As certified by the completion form dated 27^th March 2018 signed by Mr Sammy Wong (黃偉霖), who was a senior building service engineer employed by the 2^nd Defendant[17], the works under the December 2016 Engagement Letter had been completed, and the 4^th Defendant provided warranty of 5 years.

27.  Whilst the 1^st and 2^nd Defendants admit the 4^th Defendant’s assertions[18], the Plaintiffs do not seriously dispute the same.

B4. The Complaints and Events leading to the Present Action

28.  It is the Plaintiffs’ case that despite the works carried out by the 4^th Defendant, the water leakage in Flat 25D still recurred frequently (especially after rainy days). In particular:-

(1) On 20^th and 31^st March 2018, there was water leakage in multiple spots on the ceiling of Flat 25D. The Plaintiffs and/or their tenant made complaints in respect thereof.

(2) In May 2018, there was further leakage in the living room (near the window) and the dining room of Flat 25D.

(3) On 8^th June 2018, the water seepage exacerbated. Again, the Plaintiffs and/or their tenant made a complaint in respect thereof.

(4) There was persistent water seepage in the ceiling of Flat 25D from January to June 2020. As a result, there were extensive areas where flaky and peeling plasters could be seen. Further, concrete pieces fell from the ceiling.

(5) In the circumstances, the Plaintiffs and/or their tenant repeatedly complained.

29.  In light of the unsatisfactory condition of Flat 25D and the continuous water leakage problem, Mr Hung decided not to renew the tenancy, and he and his family moved out from Flat 25D on 28^th June 2020[19].

30.  The Plaintiffs say that due to the hazardous condition and risks of physical injury as well as the recurring water leakage problems, they decided not to lease out Flat 25D and not to carry out internal decoration until the water leakage problem was satisfactorily and permanently resolved[20].

31.  On 18^th January 2021, the Plaintiffs commenced the present action. When the 1^st Plaintiff testified, he stressed that whilst he sought financial compensation, his foremost objective was to pressurize the 1^st and 2^nd Defendant to take appropriate actions to eradicate the water leakage problem.

32.  It appears the 1^st and 2^nd Defendant admit that there was water seepage in Flat 25D. Their factual case is as follows[21]:-

(1) It is admitted that the Plaintiffs’ tenant complained about water leakage on 20^th March 2018. However, the moisture test conducted by the 2^nd Defendant’s staff revealed that the level of moisture was normal.

(2) It is admitted that the Plaintiffs’ tenant complained about water leakage on 8^th June 2018, and an inspection that involved the staff of the 2^nd Defendant and the staff of the 4^th Defendant took place on the same day. After the inspection, a letter was issued to the 4^th Defendant[22], and it was demanded that the water leakage problem be resolved.

(3) Had no water seepage been detected during the inspection on 8^th June 2018, the 2^nd Defendant would not have issued the said demand letter. Indeed, in the said demand letter, it was expressly recorded that there was water seepage in Flat 25D, and photos that captured the water seepage and the condition of the ceiling were attached.

(4) On 29^th July 2019, the 2^nd Defendant issued a further letter demanding the 4^th Defendant to resolve the water leakage problem in Flat 25D[23].

(5) It is admitted that on 27^th August 2019, the Plaintiffs’ tenant complained about water leakage again, and an inspection took place on the same day.

(6) On the next day (ie 28^th August 2019), the 2^nd Defendant issued a further letter demanding the 4^th Defendant to resolve the water leakage problem[24]. In the said demand letter, it was expressly stated that during the inspection on 27^th August 2019, the staff of the 2^nd Defendant saw water dripped from the ceiling in Flat 25D, and photos showing the condition of the ceiling were attached.

(7) On 15^th October 2019, the 2^nd Defendant issued another demand letter to the 4^th Defendant[25]. In this demand letter, it was recorded that the staff of the 2^nd Defendant could see the water seepage in Flat 25D, and photos showing the condition of the ceiling were attached.

(8) On 15^th December 2019 and 12^th March 2020, the 2^nd Defendant’s staff attended Flat 25D to carry out moisture tests, but the level of moisture was normal.

(9) On 3^rd January 2020, the Plaintiffs’ tenant complained about water leakage again.

(10) On 8^th April 2020, the 2^nd Defendant issued another demand letter[26] requesting the 4^th Defendant to resolve the water leakage problem. Like the previous demand letters, this demand letter recorded that during the inspection on 4^th April 2020, the staff of the 2^nd Defendant saw water dripped from the ceiling of the living room of Flat 25D, and photos showing the condition of the ceiling were attached.

(11) On 21^st May 2020, the Plaintiffs’ tenant complained about water leakage again, and the 2^nd Defendant’s staff inspected Flat 25D.

33.  The 4^th Defendant’s factual case regarding the water seepage in Flat 25D[27] is as follows:-

(1) The 4^th Defendant alleges that no water seepage was observed during the inspections that took place on 12^th, 20^th, 21^st and 30^th March 2018, 8^th June 2018 and 10^th April 2019.

(2) Despite no water seepage was observed, in light of the complaints raised by the tenant of Flat 25D, the 4^th Defendant carried out additional works in part of the drainage area on the Roof[28]. According to Mr Chiu (who was the 4^th Defendant’s foreman), he could not observe any apparent defects in the open drain on the Roof. However, based on his experience, defects in drains would cause water leakage. In the circumstances, the 4^th Defendant carried out works in respect of the open drain on the Roof, hoping that the water seepage problem would be resolved.

(3) After receiving the 2^nd Defendant’s demand letter dated 29^th July 2019, the 4^th Defendant’s staff and the 2^nd Defendant’s staff inspected Flat 25D. It was observed that there was in fact water seepage on the ceiling of Flat 25D[29].

(4) In the circumstances, in October 2019, pursuant to the 1^st and 2^nd Defendants’ request, the 4^th Defendant removed the entire concrete floor and the waterproofing membrane on the Roof, and re-applied the waterproofing membrane. The works were completed on or around 21^st November 2019[30].

(5) From 27^th to 29^th November 2019, the 4^th Defendant carried out a fluorescent dye test. On 5^th December 2019, the 2^nd and 4^th Defendant’s staff inspected Flat 25D, and no fluorescent dye was noticeable on the ceiling of Flat 25D[31].

(6) On 13^th December 2019, a further flood test was conducted. However, the 4^th Defendant was not allowed to inspect Flat 25D.

(7) Without receiving any complaint from the 1^st and/or 2^nd Defendants, the 4^th Defendant re-applied the concrete floor and surface area of the Roof on 23^rd December 2019[32].

(8) However, in January 2020, the tenant of Flat 25D complained about water leakage after a rain. In the circumstances, Mr Chiu conducted investigation. On 4^th January 2020, he discovered that there was water seepage in the external wall of the Water Tank House that contains the freshwater tank, and when the waterproofing membrane and concrete there were removed, moist and seepage could be observed. Thus, Mr Chiu orally informed the 2^nd Defendant’s staff that the recurring water seepage problems in Flat 25D could be ascribed to the defects and/or damage relating to the Water Tank Houses[33].

(9) Upon being informed about the recurring water seepage in Flat 25D, on 11^th March 2020 and 7^th, 8^th and 11^th May 2020, the 4^th Defendant carried out a fluorescent dye test. However, no fluorescent dye was noticeable on the ceiling of Flat 25D[34].

(10) On 15^th June 2020, the 4^th Defendant further removed part of the plasters on the wall of the Water Tank Houses, and it was discovered that the inner walls were wet with water seeping[35].

(11) In these premises, by the letter dated 26^th June 2020, the 4^th Defendant informed the 1^st and 2^nd Defendants that the suspected source of water leakage came from the Water Tank Houses, and the 1^st and 2^nd Defendants should repair the same[36].

B5. Development after the Present Action was Commenced

34.  As evidenced by the solicitors’ correspondence and the photos attached to the letters that were taken on 25^th June 2021[37], 30^th March 2022[38] and 10^th June 2022[39] and 21^st April 2023[40], the water leakage problem persisted after the Plaintiffs commenced the present action.

35.  In around August 2022, a contractor named Chi Tat Waterproofing Engineering Ltd (“Chi Tat”) was engaged to carry out works[41] on the Roof. Although there was no water leakage after a typhoon on 2^nd November 2022, there was serious water leakage on 21^st April 2023 after a week of heavy rainfall[42].

36.  Meanwhile, Global Generation was engaged by the 1^st and/or 2^nd Defendants. Whilst there is no documentary evidence showing when Global Generation was engaged or appointed, Mr Leung Kwok Chu (梁國柱) (who was the 2^nd Defendant’s assistant general manager) recalled that the appointment took place sometime in August 2022.

37.  According to Global Generation’s Report dated 21^st September 2022 (but revised on 9^th March 2023)[43]:-

(1) The condition of the water tanks and machine room on the Roof was poor, and water seepage was found on the external wall of the machine room and the pump room. Further, very serious concrete spalling was found in the flush water tank.

(2) It was opined that the water seepage problem was attributable to (i) failure of waterproofing membrane; (ii) the parapet wall and the flush water tank.

(3) It was recommended that the following works be carried out:-

(a) Waterproofing membrane for the floor of the Roof be reconstructed;

(b) The parapet wall (both inside and outside) and external walls of the plant room and water tank be repaired;

(c) The waterproofing membrane for the floor surface of the upper roof (ie roof of the machine room and the Water Tank Houses) be reconstructed; and

(d) Waterproofing works for the water tanks be carried out.

38.  As mentioned, on 15^th September 2023, the 1^st Defendant provided an undertaking[44] that it would carry out the recommended works set out in Global Generation’s Report. Such undertaking was recorded in the consent order made by Master Maurice Lam dated 15^th September 2023.

39.  It transpired that a new contractor, namely Yan Cheong Construction Engineering Ltd (“Yan Cheong”), was engaged by the 1^st and/or 2^nd Defendants to carry out the works recommended by Global Generation. It is not seriously in dispute that these works were carried out during the period from July 2023 to August 2024.

40.  Unfortunately, there was serious water leakage when Yan Cheong was in the course of carrying out the aforesaid works. On 13^th August 2023, it was discovered that a huge amount of broken concrete pieces fell from the ceilings of the living room, dining room and bathroom of Flat 25D[45]. As evidenced by the minutes in respect of the meeting of the 1^st Defendant’s management committee on 21^st August 2023[46], the serious water seepage was ascribed to the fact that Yan Cheong removed the existing waterproofing membrane on the Roof in the course of carrying out re-roofing works. Without any protection at all, it was unsurprising that there was serious water leakage in numerous individual units in Block 12A when there was rainfall.

41.  It is the 1^st and 2^nd Defendants’ case that all the recommended works set out in the Global Generation’s Report were completed on 30^th August 2024[47]. This is not in dispute.

42.  By the letter dated 3^th October 2024[48], the 1^st and 2^nd Defendants’ solicitors informed the Plaintiffs’ solicitors that all the reparation works on the Roof that were recommended by Global Generation had been completed. This was less than 2 weeks before the present trial commenced.

43.  When the 1^st Plaintiff testified, he said as soon as the present trial finished, he would instruct the quantity surveyor that he had already engaged to obtain updated quotations from the contractors. Upon receiving the updated quotations, he would pick one of the contractors to carry out reparation works, such that Flat 25D could be rented out as soon as possible.

C. Summary of the Positions of the Parties

C1. The Plaintiffs’ Position

Claims against the 1^st and 2^nd Defendant

44.  The Plaintiffs contend that the 1^st and 2^nd Defendants are liable for their loss and damage on the bases of:-

(1) nuisance; and

(2) breach of duties under (i) clause 5, 10(a)(7) and clauses 3 and 4(a) under the second schedule of the deed of mutual convents (the “DMC”); and (ii) section 18 of the Building Management Ordinance (Cap 344) (the “BMO”).

45.  The Plaintiffs complain that:-

(1) The new waterproofing system installed on the Roof was ineffective and not properly maintained.

(2) The pre-existing waterproofing system in other areas of the Roof (such as the external walls and the water tank kiosk) were not repaired and/or replaced[49].

(3) The 1^st and 2^nd Defendants failed to retain a reasonably competent contractor (ie the 4^th Defendant) to install the new water proofing system and failed to exercise adequate supervision[50].

(4) Despite finding out that the 4^th Defendant failed to rectify the water leakage problem, the 1^st and 2^nd Defendants failed to appoint another competent contractor and to resolve the water leakage problem[51].

(5) Despite being aware of the persisting water leakage problem, the 1^st and 2^nd Defendant failed to take reasonable and adequate measures to deal with the same[52].

46.  As a result of the water leakage (which had recurred and persisted), Flat 25D was considerably damaged. In light of the hazardous condition and the risks of physical injury, Flat 25D has not been suitable for habitation, and the Plaintiffs could not rent out Flat 25D for rental income.

47.  In the premises, the Plaintiffs has suffered loss and damage, and they seek damages against the 1^st and 2^nd Defendants.

Claims against the 4^th Defendant

48.  The Plaintiffs also allege that their loss and damage were attributed to the negligence on the part of the 4^th Defendant[53]. They say that the 4^th Defendant’s works on the Roof were unsatisfactory and that the steps for carrying out these works were inadequate. It is also alleged that the 4^th Defendant failed to take reasonable and/or appropriate steps to stop the water leakage.

49.  In the premises, the Plaintiffs also seek damages against the 4^th Defendant.

C2. The 1^st and 2^nd Defendants’ Position

50.  Mr Wong (for the 1^st and 2^nd Defendants) accepts that based on the evidence from the 3 experts engaged by the parties, there was water leakage in Flat 25D, though the extent of the water leakage is disputed.

51.  Whilst Mr Wong suggests that the sole cause of the water leakage was the alleged defects in respect of the waterproofing membrane installed by the 4^th Defendant, he contends that the 1^st and 2^nd Defendants are not liable to the Plaintiffs at all as the 1^st and 2^nd Defendants acted reasonably in (i) engaging the 4^th Defendant to carry out the reparation works; and (ii) repeatedly giving instructions to the 4^th Defendant to resolve the water leakage problem and to carry out further remedial works.

52.  As a fallback, pursuant to the amended notice of contribution and/or indemnity dated 4^th November 2022, the 1^st and 2^nd Defendants contend that if they were held liable for the Plaintiffs’ loss and damage, they would seek contribution and/or indemnity against the 4^th Defendant. In this connection, the 1^st and 2^nd Defendants contend that the 4^th Defendant failed to fulfill the contractual obligations under the December 2016 Engagement Letter competently, in that he failed to apply good workmanship, remedy the water leakage problem and identify the source of the water leakage[54].

53.  Insofar as the loss and damage suffered by the Plaintiffs are concerned, Mr Wong contends that the Plaintiffs have failed to mitigate their loss reasonably. In this connection:-

(1) Relying on the opinion expressed by their expert namely Dr Eddie Lam, Mr Wong contends that Plaintiffs should have injected specialized waterproofing materials with crystallization ability to stop ingress of water[55].

(2) Mr Wong further contends that the Plaintiffs should have commenced reparation and renovation works after receiving the letter dated 30^th April 2024 from the 1^st and 2^nd Defendants’ solicitors[56]. In this letter, it was pointed out, inter alios, that certain recommended works set out in Global Generation’s Report, including the reparation of the external walls surrounding the Water Tank Houses and the reparation of part of waterproofing layer for the floor surface of the upper roof[57], were completed. Mr Wong points out that the Plaintiffs’ expert, namely Ms Lau Shan La (hereinafter “Ms Lau”), suggests that the damage to the external walls surrounding the Water Tank Houses was one of the alleged causes of water leakage. Thus, based on the opinion of their own expert, the Plaintiffs should have commenced reparation and renovation works after the said damage was repaired.

C3. The 4^th Defendant’s Position

54.  Like the 1^st and 2^nd Defendants, the 4^th Defendant does not seriously dispute that there was persistent water leakage in Flat 25D.

55.  However, the 4^th Defendant strenuously denies that the works carried out pursuant to the 2016 Engagement Letter were defective and/or sub-standard.

56.  Mr Stephen Siu (for the 4^th Defendant) contends that the cause of the water leakage was (i) the defects and/or damage in respect of the waterproofing membrane in the walls of the Water Tank Houses; and (ii) the defect and/or damage in respect of the external walls of Block 12A.

57.  Mr Siu also stresses that as evidenced by the 1^st and 2^nd Defendants’ own meeting minutes on 21^st August 2023[58], the serious water leakage on 13^th August 2023 was ascribed to the fact that Yan Cheong removed the existing waterproofing membrane on the Roof in the course of carrying out re-roofing works. As such, the 4^th Defendant could not be held liable for any loss or damage in respect thereof.

D. Relevant Legal Principles

D1. Burden of Proof

58.  It is well established there is no presumption that the source of the water leakage must come from the premises immediately above: see 張秀玲 訴 鄭禮莊 (CACV 268/1998 9^th April 1999) at para 21 (per Leong JA, as he then was).

59.  The onus is on the plaintiff to prove or establish that the leakage originated from the defendant’s property, and it is not for the defendant to identify the source of the leakage: see Hui Ling Ling v Sky Field Development Ltd (CACV 122/2012, 22^nd March 2023) at para 42 (per Kwan JA, as she then was).

D2. Nuisance

60.  The “essence of nuisance is a condition or activity which unduly interferes with the use and enjoyment of land”: Clerk & Lindsell on Torts (24^th Ed) at para 19-01.

61.  The learned authors of Clerk & Lindsell on Torts (24^th Ed) pointed out that (see para 19-05):-

“private nuisance may be and usually is caused by a person doing on his own land something which he is lawfully entitled to do. His conduct becomes a nuisance when the consequences of his act are not confined to his own land but extend to the land of his neighbour by: … (2) causing physical damage to his neighbour’s land/building and works upon it; or (3) unduly interfering with his neighbour’s comfortable/convenient enjoyment of his land.”:

62.  The courts have repeatedly held that water leakage can constitute nuisance: see eg 張秀玲 訴 鄭禮莊 (supra) at para 26 (per Liu JA).

63.  The liability for nuisance is not strict or absolute. If an owner or occupier nullifies the nuisance emanating from his land without undue delay after he became aware of it, he would not be liable. In Sedleigh-Denfield v O'Callagan & ors [1940] AC 880 at 904 to 905, Lord Wright stated:-

“…… The liability for a nuisance is not, at least in modern law, a strict or absolute liability. …… But he may have taken over the nuisance , ready made as it were, when he acquired the property, or the nuisance may be due to a latent defect or to the act of a trespasser, or stranger. Then he is not liable unless he continued or adopted the nuisance , or, more accurately, did not without undue delay remedy it when he became aware of it. This rule seems to be in accordance with good common sense and convenience.”

(see also: Leakey & ors v National Trust for Places of Historic Interest or Natural Beauty[1980] 1 QB 485, 517-518 (per Megaw LJ); Loke Yuen Jean Tak Alice v Wong Kit Ying & Ors [2019] HKCFI 1895 at para 55 (per Marlene Ng J) )

64.  However, if the defendant has knowledge that the nuisance emanates from his land but fails to take reasonable steps to nullify or abate the same within a reasonable time, he will be liable. In Sedleigh-Denfield v O'Callagan & ors (supra) at pp.894-895, Viscount Maugham stated:-

“The statement that an occupier of land is liable for the continuance of a nuisance created by others, e.g., by trespassers, if he continues or adopts it — which seems to be agreed — throws little light on the matter, unless the words “continues or adopts” are defined. In my opinion an occupier of land “continues” a nuisance if with knowledge or presumed knowledge of its existence he fails to take any reasonable means to bring it to an end though with ample time to do so…”

(see also: Loke Yuen Jean Tak Alice v Wong Kit Ying & Ors (supra) at para 55; Yik Yuen Ling v Tso Wing Yan (DCCJ 813/2004, 18^th October 2017) at paras 149-150 (per Deputy District Judge Simon Ho)

65.  Thus, a defendant who does not have actual or constructive knowledge that the water seepage emanated from his property is not liable. However, once the defendant has the requisite actual or constructive knowledge, he will be liable unless remedial action is taken without delay: see Leung Wai Kee & Anor v Tam Yuen Sheng (DCCJ 5716/2007, 10^th July 2012) at para 43 (per Deputy District Judge Grace Chan); Tin Kin Ka Clara v Chan Koon Cheong & Anor (DCCJ 3139/2012, 11^th May 2015) at paras 54 to 55 (per His Honour Judge Andrew Li).

66.  In 張秀玲 訴 鄭禮莊 (supra) at para 26, Liu JA explained the requisite actual knowledge and constructive knowledge as follows:-

“26. 漏水可能導致「滋擾」，而法律就這項目有很明確的規範。簡單地說，有以下幾種普遍情況：

(1) 若漏水是在一處地方（包括樓宇單位）中發生，招致鄰舍（包括另一單位）損失時，而事源地方的戶主（是使用該地方的人，不一定需要是業主）明知漏水根源，他便是有意圖滋擾而須負法律責任。法律責任包括賠償及受禁制令禁制。

(2) 若漏水不是事源地方戶主自己或自己應代為負責的人所招致，而他又不知道漏水已發生，他就不須對漏水所招致鄰舍的損失負責。

(3) 若漏水不是事源地方戶主自己或自己應代為負責的人所招致，當他知道漏水源於他單位內，他須在無合理延誤下作出補救。否則，他須為該項漏水所招致鄰舍的損失負上法律責任。

(4) 以上三項中的「知道」，是指兩種情況：(a) 是實質地知道，或 (b) 是在通常及合理謹慎下應可知道。故此，就算戶主實質上不知道漏水的存在，因為他不在事源地方，他也不能藉此推卸責任。他身為戶主，對自己使用的地方要負法律責任。若在通常的情況下戶主應可知道有關使用地方的情況，在法律上他就被當作知情。作為地方的戶主，他應對該地方作出合理謹慎的處理。故此，對該地方的情況而言，一切他應在合理謹慎下可知道的，法律也當他知道。

(5) 第 (2) 和第 (3) 項所述的「戶主應代為負責的人」，是指一切戶主准許進入或使用戶主地方的人，包括他的家人、朋友、僱員和入內工作的人，但不包括未獲他或上述的人准許而進入地方的人。”

67.  It is often said that an owner or occupier has a duty to nullify or abate the nuisance originating from his land. In the context of public nuisance, in Leung Tsang Hung and Lee Wai Yu v The Incorporated Owners of Kwok Wing House (2007) 10 HKCFAR 480 at para 25, Ribeiro PJ held that whilst such duty or obligation is not strict or absolute, it is “non-delegable”. His Lordship stated:-

“It is also important not to confuse strict or absolute liability with liability arising under a non-delegable duty. Where a defendant is under a duty to nullify a nuisance…, that duty is non-delegable. He remains liable even though he has engaged an apparently competent independent contractor to eliminate the nuisance hazard if, through the latter’s negligence or otherwise, the hazard is not in fact removed, resulting in injury to the plaintiff.” (emphasis added)

68.  In Leung Tsang Hung v IO of Kwok Wing House (supra), an illegal structure that was affixed onto the external wall of a building collapsed. As a result, a hawker on the street was killed. The collapse was ascribed to “want of repair” of the relevant structures (see paras 2 to 7 of the judgment).

69.  Bearing in mind the context of Leung Tsang Hung v IO of Kwok Wing House (supra), I see no logical reason why Ribeiro PJ’s dictum set out in paragraph 67 above is not applicable to private nuisance. Both public nuisance and private nuisance are legal wrongs, and they may cause financial loss, inconvenience, discomfort and physical injury (or even death) to innocent parties. There is every reason why a nuisance, whether private or public, should be nullified or abated once the landowner or occupier has actual or constructive knowledge in respect thereof.

D3. Duties to Manage and Maintain Common Parts of Buildings

70.  Section 18(1) of the BMO provides that incorporated owners have a statutory duty to maintain the common parts of the building. It reads as follows:-

“(1) The corporation shall—

(a) maintain the common parts and the property of the corporation in a state of good and serviceable repair and clean condition;

(b) carry out such work as may be ordered or required in respect of the common parts by any public officer or public body in exercise of the powers conferred by any Ordinance;

(c) do all things reasonably necessary for the enforcement of the obligations contained in the deed of mutual covenant (if any) for the control, management and administration of the building.”

71.  Section 34I of the BMO provides that:-

“(1) No person may—

(a) convert any part of the common parts of a building to his own use unless such conversion is approved by a resolution of the owners’ committee (if any);

(b) use or permit to be used the common parts of a building in such a manner as—

(i) unreasonably to interfere with the use and enjoyment of those parts by any owner or occupier of the building; or

(ii) to cause a nuisance or hazard to any person lawfully in the building.

(2) Any person who contravenes subsection (1) shall be deemed to be in breach of an obligation imposed on him by the deed of mutual covenant in respect of the building.”

72.  In Lau Chun Wing Rod v The Incorporated Owners of Po On Building (CACV 20/2007, 1^st November 2007) at paras 12 to 13, Rogers VP held that the incorporated owners would breach the duties under section 18(1)(a) of the BMO and liability might arise if it is aware of the defect or despair condition of the common parts of buildings but fail to take appropriate steps. His Lordship stated:-

“12. This sub-section does not provide an insurance to the extent that if some part of the building becomes in disrepair the Incorporated Owners automatically and necessarily become liable. Nevertheless, liability may arise if there is fault. It also arises if, having been made aware of a defect which requires remedy, the Incorporated Owners fail to take appropriate steps. On the judge’s finding the defendant did so fail to take appropriate steps. Likewise it would seem that the case in negligence and nuisance is, on the facts, clear.

13. In view of the way in which the appeal was presented, it was pointed out that the judge had not held that the defendant was liable simply because there was some defect that became apparent in the premises. He held the defendant was liable because it failed to act effectively when it should have taken action. What is required to be done in carrying out the duty will differ according to the circumstances but in this case the judge clearly held that the defendant failed to take proper and necessary steps at a time when it had been alerted that it was necessary to do so and that it continued to fail in that regard for a very lengthy period.”

73.  In Lo Yuk Chu v Hang Yick Properties Management Ltd [1996] 4 HKC 278 at 281-282E, Power ACJ held that the manager’s duty to properly manage the common part of the building under the DMC was not absolute, and the duties entailed “doing all that is reasonably required of a manager in the circumstances”.

D4. Mitigation

74.  It is trite that the law requires a victim to take all reasonable steps to mitigate the loss arising from the defendant’s wrong, and whether the loss is avoidable by reasonable action on the part of the plaintiff is a question of facts: see McGregor on Damages (19^th Ed) at paras 9-014 and 9-016.

75.  As pointed out by the learned authors of Clerk & Lindsell on Torts (24^th Ed) at para 26-09:-

“[t]he onus is on the defendant to show that the claimant failed to mitigate and much will depend on what the court regards, in the circumstances, as being reasonable. Judges are reluctant to impose excessive demands on the claimants.”

E. Deliberation

E1. The Extent of Water Leakage

76.  As mentioned, it is not seriously in dispute that there was water leakage in Flat 25D. The water leakage is evidenced by ample contemporaneous evidence.

77.  Mr Vincent Li (for the Plaintiffs) draws my attention to a series of photos showing the physical condition of the living room, dining room, guest bathroom and kitchen of Flat 25D throughout the years. These photos were taken on 2^nd January 2016[59], 3^rd February 2018[60], 2^nd February 2018[61], 12^th March 2018[62], 17^th March 2018[63], , 30^th May 2018[64], 8^th June 2018[65], 27^th August 2019[66], 3^rd January 2020[67], 12^th March 2020[68], 21^st May 2020[69], 1^st September 2020[70], 24^th June 2021[71], 29^th March 2022[72], 21^st April 2023[73], 10^th June 2022[74] and 13^th August 2023[75].

78.  These photos, which are incontrovertible, show that:-

(1) The plasters on the ceiling and walls crumpled, and there were cracks.

(2) There were extensive areas of peeling and flaking plaster on the ceiling and walls.

(3) There was spalled concrete at the ceiling.

(4) Broken concrete pieces of considerable size fell from the ceiling.

(5) The steel reinforcement embedded in the ceiling was exposed.

79.  I have no doubt that there was serious water leakage in Flat 25D, and the physical condition was unsatisfactory. It was obvious that the damage to Flat 25D was caused by the serious water leakage, which had continued for years.

80.  The water seepage was recorded in and evidenced by the contemporaneous documents:-

(1) As mentioned, the 2^nd Defendant issued a series of letters dated 8^th June 2018[76], 29^th July 2019[77], 28^th August 2019[78], 15^th October 2019[79] and 8^th April 2020[80] to the 4^th Defendant requesting that the water leakage problem be resolved. In these letters, the water seepage in Flat 25D was recorded.

(2) In the tenancy agreements between the Plaintiffs and Mr Hung dated 11^th June 2018 and 20^th June 2020[81], the parties added hand-written provisions stating that due to the water seepage and the damage to Flat 25D, the monthly rental was reduced (i) by HK$9,200 from HK$28,000 to HK$18,800 (insofar as the period from June 2016 to June 2018 was concerned); and (ii) by HK$6,800 from HK$32,000 to HK$25,200 (insofar as the period after June 2018 was concerned).

(3) Further, the 1^st tenancy agreement contained an additional hand-written clause providing that the tenant could give one-month notice to terminate the tenancy before the 2^nd Defendant issued a notice to confirm that the reparation works on the Roof were completed. Similarly, the 2^nd tenancy agreement contained an additional hand-written clause providing that the tenant could give one-month notice to terminate the tenancy if there was still water seepage after rain.

(4) There is no question that the water seepage problem in 25D was serious. This was the reason why (as evidenced by the tenancy agreements), the Plaintiffs gave considerable rental reduction to Mr Hung and allowed him to have the flexibility of terminating the tenancy by giving 1-month notice.

(5) Furthermore, the water seepage after the present action was started has been recorded in the solicitors’ correspondence as well as the photos annexed thereto.

81.  Insofar as the opinion of the parties’ experts is concerned:-

(1) The Plaintiffs’ expert, Ms Lau, and her colleagues inspected Flat 25D on 1^st September 2020, 2^nd September 2020, 3^rd September 2020 and 22^nd September 2020. They used the following methods to ascertain whether there was water leakage and the extent of the water leakage: (i) visual inspection; (ii) infrared scan; (iii) electrical conductivity sensing; (iv) microwave scan; and (v) fluorescent dye test. Ms Lau opined that as of September 2020, there was water leakage in the ceilings of the living room, dining room and guest bathroom in Flat 25D. When Ms Lau testified, she said that she focused on these areas because the Plaintiffs complained that there was water seepage there at the time.

(2) The 1^st and 2^nd Defendants’ expert, namely Dr Eddie Lam, inspected Flat 25D on 17^th January 2022. He used a protimeter to measure the moisture level and conducted a “tapping test” on the ceiling. He also took into account the complaints made by the Plaintiffs in the past and the physical appearance of Flat 25D (with spalling, exposed reinforcements delamination and dried-up watermarks). Dr Lam opined that there was water leakage in the ceilings of the living room and dining room.

(3) According to his report, the 4^th Defendant’s expert, namely Mr Chung Wai Hoi (“Mr Chung”), inspected Flat 25D on 19^th January 2022, 21^st January 2022 and 17^th February 2022. Whilst he conducted a fluorescent dye test, he also used the methods of electrical conductivity sensing and infrared scan to ascertain whether there was water leakage and the extent thereof. Mr Chung opined that there was only water seepage in the ceiling of the dining room and living room. Sadly, Mr Chung passed away shortly before the present trial commenced. As such, the parties agreed that Mr Hau Tung Chow (“Mr Hau”) (who adopted Mr Chung’s opinion) could testify in the capacity as the 4^th Defendant’s expert.

82.  In her report dated 23^rd October 2020, Ms Lau provided detail explanations as to the tests that she and her staff carried out and the methodologies in respect thereof. Ms Lau’s opinion is consistent with the factual evidence (such as the photos that show the physical condition of Flat 25D). I accept Ms Lau’s opinion that there was water seepage in the dining room, living room and guest bathroom of Flat 25D as of September 2020.

83.  I also accept Ms Lau’s evidence that she saw sizeable concrete pieces on the floor in Flat 25D when she inspected Flat 25D on 21^st February 2022 for the purpose of assessing the damage to Flat 25D. Ms Lau observed that as of February 2022, the condition of Flat 25D had deteriorated since her previous inspection in September 2020. She opined that the further damage to Flat 25D caused by the continuous water seepage. Having reviewed the photos showing the condition of Flat 25D in April 2023[82], Ms Lau also opined that there was still water seepage in Flat 25D as of April 2023 and that the further damage to Flat 25D was caused by the persistent water seepage. In this connection, Ms Lau’s opinion is consistent with Mr Hau’s opinion. Upon considering the photos that showed the high protimeter readings in April 2023, Mr Hau also opined it was likely that there was still water seepage in Flat 25D as of April 2023. The aforesaid opinion expressed by Ms Lau and Mr Hau makes sense, and I accept the same.

84.  However, Dr Eddie Lam opined that the photos taken in April 2023[83] did not show continuous water seepage at all. He said that (i) the high level of moisture could be ascribed to sea wind and the moss that was developed and (ii) the collapsed concrete pieces could be ascribed to structural defects. Dr Lam’s views are pedantic and unreal. I am unable to accept the same. I prefer Ms Lam and Mr Hau’s views and opinion set out in the paragraph immediately above, which are more consistent with the factual evidence as well as common sense.

85.  Relying on Dr Lam’s opinion, Mr Wong submits it can only be proved that there was only water seepage in the living room, dining room and guest bathroom before January/February 2022. Mr Wong effectively suggests that the Plaintiffs have failed to prove continuous water leakage as the experts did not continuously inspect the premises from time to time. He also effectively asks me to ignore the incontrovertible or unchallenged factual evidence, such as the photos (which recorded the appalling conditions in Flat 25D) and the correspondence (which recorded the incidents of water leakage after heavy rainfall). Mr Wong’s approach is pedantic and unreal. I reject his submissions.

86.  Having considered the factual evidence and the experts’ opinion, I find that:-

(1) Despite the settlement in DCCJ 2246/2014 and the works carried out by the 4^th Defendant on the Roof pursuant to the 2016 Engagement Letter (which had been completed as of 26^th March 2018), the water leakage problem had not been resolved.

(2) There had been serious water seepage in Flat 25D from March 2018 onwards, and the locations that were affected by water seepage included the dining room, living room, guest bathroom, kitchen and bedroom.

(3) As of September 2020, there was water seepage in the ceilings of the dining room, living room and guest bathroom.

(4) The water seepage had persisted and recurred. I do not accept the suggestion that there had been no water seepage after 2022. The incontrovertible evidence (which I accept) shows that there was still very serious water seepage as of April 2023, June 2023 and August 2023[84].

(5) The water seepage caused considerable damage to Flat 25D. The damage was so serious that broken concrete pieces fell from the ceiling, and there were spalled concrete and exposed steel embedment. These conditions (and as well as the conditions mentioned in paragraph 78 above) were caused by the continuous water seepage.

(6) The water seepage caused substantial interference to the use and enjoyment of Flat 25D. In light of the danger and hazardous condition, Flat 25D was no longer habitable as of June 2020.

E2. The Source(s) and Cause(s) of the Water Leakage

87.  The next issue to determine is what the source(s) and cause(s) of the water seepage in Flat 25D were.

88.  As pointed out, the Roof is above Flat 25D, and all the structures thereon (such as the Water Tank Houses and the Staircase House) are common parts of Provident Centre.

89.  As evidenced by the correspondence amongst the parties (including the solicitors’ letters, the 2^nd Defendant’s demand letters to the 4^th Defendant and the 4^th Defendant’s letter dated 26^th June 2020 to the 1^st Defendant[85]), it is not in dispute that the source of the water seepage in Flat 25D was the Roof.

90.  The controversial question is whether the water seepage emanated from a location or locations on the Roof that fell within the 4^th Defendant’s scope of works under the 2016 Engagement Letters. As will be elaborated in Sections E3 to E5 below, the answer to this question has important bearing on the liabilities (if any) on the part of the 1^st, 2^nd and 4^th Defendants.

Factual Evidence and Inherent Probabilities

91.  The 1^st Plaintiff said that throughout the years, there was often serious water seepage in Flat 25D shortly after heavy rains. In the 1^st Plaintiff’s own words, this was a “salient feature” of the situation that he and his wife faced.

92.  I have no doubt that the 1^st Plaintiff (who is an honest and impressive witness) told me the truth. His evidence is corroborated by the contemporaneous documents. For instance:-

(1) In October 2019, the 4^th Defendant redid the waterproof works on the Roof (as required under the 2016 Engagement Letter), and the water flush test that was carried out from 27^th to 29^th November 2019[86] showed that there was no sign of water leakage.

(2) In the circumstances, the Plaintiffs were asked to sign an acknowledgement. Although the Plaintiffs agreed to sign the acknowledgement on 23^rd November 2019[87], they added hand-written words in the document to put on record that despite the water flush test was completed, there had been no rainfall so far, and as such it was uncertain whether the waterproofing system on the Roof functioned.

(3) This document corroborates the 1^st Plaintiff’s evidence that there were many incidents where there was serious water seepage after heavy rains. This was why the Plaintiffs felt skeptical despite the water flush test in late November 2019 showed no sign of water leakage.

93.  Due to their unpleasant experience, the Plaintiffs were concerned about rainfall more than the outcomes of fluorescent dye tests. After Mr Hui and his family left in June 2020, the 1^st and 2^nd Plaintiffs often inspected Flat 25D after heavy rains, and there were many occasions where serious water seepage was seen. For instance, as recorded in the letter dated 8^th May 2023 from the Plaintiffs’ solicitors and evidenced by the photos attached thereto[88], after heavy rainfall in the week starting on 17^th April 2023, there were flaky plasters and spalled concrete on the ceilings in the living room and kitchen and collapsed concrete pieces were all over the place.

94.  Indeed, it is the 1^st and 2^nd Defendant’s case that fluorescent dye tests (which were also colloquially called “flush tests”) were conducted in February 2018, November 2019, March 2020 and May 2020 after the 4^th Defendant carried out works on the Roof[89]. The result was that there was no sign of water leakage. The Plaintiffs’ expert, Ms Lau, and the 4^th Defendant’s expert, Mr Chung, also respectively conducted fluorescent dye tests in September 2020 and January/February 2022. Both experts concluded that the fluorescent dye tests did not reveal water leakage. This tends to show that the works carried out by the 4^th Defendant were not defective.

95.  Mr Chiu (who testified for the 4^th Defendant) fairly accepted that from his experience, the outcome of fluorescent dye tests was not conclusive. He said that even if a fluorescent dye test did not reveal any sign of water leakage, it could not be concluded that the waterproofing membrane was impeccable, and there were various reasons why the fluorescent dye did not appear on the ceilings of the subject property. For instance, the florescent dye could be blocked and/or absorbed by the materials in the slap. In this regard, Mr Chiu’s evidence is consistent with Ms Lau’s opinion.

96.  It is curious as to why the water leakage problem was not resolved despite repeated attempts to carry out re-roofing works and/or reparation/remedial works throughout the years. From 2011 to 2022, three contractors, namely SKY, the 4^th Defendant and Chi Tat[90], had been engaged to carry out works on the Roof. As pointed out by Dr Eddie Lam[91], prior to 2022 there were no less than 12 attempts to repair the Roof and/or to carry out remedial or additional works.

97.  In my view:-

(1) It was inherently unlikely that all the contractors that were involved were incompetent and/or negligent, and all the works that they carried out throughout the years were defective and/or sub-standard.

(2) It was even more unlikely that whilst all the works carried out by all the contractors (including the 4^th Defendant) were sub-standard and/or defective, coincidentally the fluorescent dye tests that were conducted on the floor of the Roof by the contractors and the experts throughout the years did not show any sign of water leakage. This was too much a sheer coincidence.

98.  Whilst the Plaintiffs suggest that the 4^th Defendant’s negligence and/or defective workmanship was one of the three factors that caused the water leakage, the 1^st and 2^nd Defendants suggest that the water leakage was solely ascribed to the 4^th Defendant’s negligence and/or defective workmanship.

99.  However, the accusations made by the Plaintiffs and the 1^st and 2^nd Defendants are completely hollow. Their pleadings are devoid of any meaningful particulars that shed light on the substance of their accusations. The Plaintiffs and the 1^st and 2^nd Defendants have been unable to pinpoint the steps or procedures that the 4^th Defendant should have adopted or implemented but failed to adopt or implement. They are unable to identify any material that was inappropriate and/or sub-standard.

100.  Both Mr Li (for the Plaintiffs) and Mr Wong (for the 1^st and 2^nd Defendants) extensively cross-examined Mr Chiu. In my view, Mr Chiu was an honest and helpful witness. At the time when the present trial took place, Mr Chiu no longer worked for the 4^th Defendant[92]. He has no interest in the outcome of the present action. This explains why Mr Chiu was candid. He was simply unshaken during cross-examination.

101.  As the 4^th Defendant’s foreman, Mr Chiu supervised the workers who carried out works on the Roof, and after the workers completed a stage of works, he checked and verified the same. He was responsible for liaising with the 2^nd Defendant’s engineering staff, and he knew about the technical aspects of the works very well. Despite the lapse of time, Mr Chiu had good recollection about the details of the works that were carried out on the Roof. He provided convincing answers to the questions put to him. For instance, Mr Wong (for the 1^st and 2^nd Defendants) suggested that the fluorescent dye test carried out in March 2020 was not thorough as a photo taken on 11^th March 2020[93] appeared to show that the fluorescent dye did not reach the L-shape juncture (腳線) between the bottom of the Water Tank Houses and the floor of the Roof. Mr Chiu immediately rebutted this suggestion. He confirmed that the said L-shape juncture (腳線) was tested, and he, in detail, explained why due to the inclination on the Roof, it was necessary to carry out the fluorescent dye test on a zone-by-zone basis. Thus, it would not be fair for the 1^st and 2^nd Defendants to raise a criticism based on the image shown in a single picture. Mr Chiu was able to explain the details in respect of steps and procedures that the 4^th Defendant adopted in constructing and re-constructing the floor on the Roof as well as the L-shape juncture (腳線). He, in detail, explained the materials that were used and the functions as well as features thereof. Mr Chiu also explained why it was beneficial to add another layer of waterproofing protection on the surface of the open drain on the Roof, and the details of the procedure (which would not affect the internal waterproofing system and/or materials) were explained clearly.

102.  Having heard Mr Chiu’s evidence and observed the way in which he spontaneously responded to the questions from Mr Wong and Mr Li, I am of the view Mr Chiu was a responsible employee who was serious about his duties, and he closely monitored the work process. Although Mr Chiu was not a qualified engineer, I am of view that if there was any abnormality in respect of the works on the Roof or if these works deviated from the required or usual procedure, the same would not have escaped Mr Chiu’s attention and would have been rectified.

103.  Mr Chiu mentioned that he worked closely with Mr Samson Wong, who was a qualified building service engineer and who worked in Provident Centre. In this connection, it is not in dispute that Mr Samson Wong was employed by the 2^nd Defendant and he oversaw the waterproofing works in relation to the Roof on Block 12A. I accept Mr Chiu’s evidence that (i) Mr Samson Wong checked the works carried out by the workers engaged by the 4^th Defendant at each stage, and he provided comments in respect thereof (which were addressed by the 4^th Defendant); and (ii) the 4^th Defendant only proceeded to carry out the next stage of works upon obtaining the confirmation from Mr Samson Wong.

104.  Despite the Plaintiffs’ complaint of water seepage on 20^th March 2018, Mr Samson Wong signed a completion form 7 days afterwards on 27^th March 2018[94]. It appears that Mr Samson Wong, who was responsible for supervising the 4^th Defendant, did not take the view that the water seepage in question was related to the 4^th Defendant’s works. Had there been any apparent defect and/or inadequacy in respect of the works carried out by 4^th Defendant, Mr Samson Wong would not have signed the said completion form shortly after the Plaintiffs complained about water seepage again.

105.  However, the Plaintiffs and the 1^st and 2^nd Defendants insist that the works carried out by the 4^th Defendant were defective and/or sub-standard. In my view, none of their contentions has merits.

106.  When Mr Li (for the Plaintiffs) cross-examined Mr Chiu, he pursued an attack along the line that the 4^th Defendant negligently sub-contracted the waterproofing works under the 2016 Engagement Letter to sub-contractors (including a Mr Chan), and the supervision exercised by the 4^th Defendant was inadequate and/or ineffective.

107.  I am not persuaded by Mr Li’s contention:-

(1) Mr Li’s submission is based on Mr Chiu’s mistaken admission that Mr Chan could be regarded as the 4^th Defendant’s sub-contractor as he did not sign an employment contract and did not receive MPF. The distinction between independent contractor and employee is a legal question, and it is understandable why Mr Chiu was initially mistaken when he gave oral evidence.

(2) When Mr Chiu had the opportunity to clarify the position, he made it clear that Mr Chan always abided by his instructions, and he had no control as to how he carried out the works assigned to him. Further, Mr Chan received salary on a daily basis, not on a “task-by-task” basis. Mr Chiu also pointed out that there were many other workers who were involved in the works on the Roof, and the reason why he sent Mr Chan to Flat 25D on a few occasions was that Mr Chan knew the locations of the structures on the Roof, such as the Water Tank House.

(3) Mr Chiu’s evidence is consistent with the evidence of Mr Pang Tin Chun (彭天頌) (“Mr Pang”), who took the over the matters in respect of the Roof on Block 12A when Mr Chiu was about to leave the 4^th Defendant (which took place around mid-2020). Mr Pang mentioned that before Mr Chan was assigned to carry out works in Provident Centre, he together with another junior worker with surname Tam worked under him in relation to the waterproofing works in an estate in Tai Wai, and they always abided by his instructions. Mr Pang also pointed out that had Mr Chan and Mr Pang been sub-contractors, it would not have been necessary for him to supervise them on a continuous basis. Mr Pang also mentioned that there were many workers who had been involved in the waterproofing works on the Roof for years, and the project would have been chaotic and unmanageable had all of them been sub-contractors who worked on a “task-by-task” basis.

(4) I accept the evidence of both Mr Chiu and Mr Pang, which makes perfect sense. On the evidence, Mr Chan as well as Mr Tam were obviously the 4^th Defendant’s employees. I reject Mr Li’s contention that the 4^th Defendant sub-contracted any part of the works under the 2016 Engagement Letter to sub-contractors. This contention is not borne out by the evidence at all.

(5) In any event, even if the 4^th Defendant sub-contracted part of the works under the 2016 Engagement Letter to sub-contractors and Mr Chan was one of these sub-contractors as alleged (which was not the case), it does not mean that the 4^th Defendant was negligent in supervising them or that the works on the Roof were defective. As pointed out, the Plaintiff (as well as the 4^th Defendants) have been unable to identify what the alleged defect(s) in respect of the waterproofing works on the Roof was/were about.

108.  When Mr Wong (for the 1^st and 2^nd Defendants) cross-examined Mr Chiu, he suggested that the 4^th Defendant was willing to (i) carry out works relating to the open drain on the Roof in May 2019; and (ii) re-do the entirety of the waterproofing works on the Roof in October 2019 because the 4^th Defendant knew that the previous works on the Roof were defective.

109.  I do not accept Mr Wong’s suggestion:-

(1) First of all, as mentioned, the Plaintiffs and the 1^st and 2^nd Defendants are simply not in a position to pinpoint the alleged defect(s). I cannot see how the 4^th Defendant could have accepted that the works on the Roof were defective when the 1^st and 2^nd Defendants (as well as the Plaintiffs) have been unable to point out what the alleged defect(s) was/were about.

(2) In any event, I accept Mr Chiu’s explanations as to why the 4^th Defendant agreed to carry out further works on the Roof in May 2019 and October 2019.

(3) It is not in dispute that apart from the works on the Roof of Block 12A, at the material times the 4^th Defendant was one of the contractors engaged by the 1^st Defendant to carry out a series of renovation works to revamp the entire estate. Since Provident Centre comprised 17 residential buildings, this was a huge project.

(4) Mr Chiu stressed that he and his colleagues took the view that the recurring water seepage problem in Flat 25D had nothing to do with the works carried out by the 4^th Defendant. However, with a view to maintaining a harmonious relationship with 1^st and 2^nd Defendants and enabling the 4^th Defendant to collect payments from the 1^st and 2^nd Defendants in relation to other works in a smooth and amicable manner, Mr Chiu’s supervisors instructed him to accommodate the 1^st and 2^nd Defendants as much as possible, and to ascertain what could be done in order to appease the 1^st and 2^nd Defendants.

(5) It was in these circumstances that Mr Chiu arranged workers to add an external layer of waterproofing materials onto the open drain at the Roof in May 2019. Mr Chiu said that the location of the open drain was not far away from the area above Flat 25D, and it was common that defects in drain would cause water leakage. Since it would be quick and straightforward to add an additional layer of waterproofing protection on the surface of the open drain and the internal waterproofing system would not be affected, Mr Chiu believed that it made sense to carry out these works and see whether the water seepage would stop. However, the water seepage problem persisted. As such, in October 2019 the 4^th Defendant’s workers demolished the pre-existing waterproofing membrane on the Roof and redid all the waterproofing works.

(6) I accept Mr Chiu’s evidence. His evidence makes commercial sense and is consistent with the undisputed facts that the 4^th Defendant was engaged to carry out other works under the project to revamp the Provident Centre and that there were disputes relating to the sums payable in respect of these works.

110.  I do not lose sight of Dr Eddie Lam[95] and Ms Lau’s[96] observations and/or assertions that the waterproofing works carried out by the 4^th Defendant were defective and/or sub-standard. In my view, their observations and/or assertions have no substance and are plainly untenable.

(1) Insofar as Dr Eddie Lam’s observations and assertions are concerned:-

(a) Dr Lam has not investigated the process through which the 4^th Defendant’s works were carried out and the materials there were used; nor has he inspected the Roof for the purpose of analyzing whether the waterproofing works there were defective. Dr Lam’s views and observations are based some photos that were taken from 22^nd May 2019 to 15^th October 2020[97] and the contractual provisions in the tender documents.

(b) Since Dr Lam was not provided with the photos that were taken prior to 22^nd May 2019, he is not in a position to criticize the works that the 4^th Defendant carried out prior 22^nd May 2019. He has no basis to raise any criticism and/or express any opinion in respect thereof.

(c) As regards the subsequent works that were carried out from 22^nd May 2019 to 15^th October 2020, based on the images that appear in the photos, Dr Lam suggests that the 4^th Defendant, inter alios, failed to repair defective concrete and only applied waterproofing works on the surface[98].

(d) I cannot see how Dr Lam could rely on the images in the photos to conclude the 4^th Defendant’s works were defective, problematic and/or sub-standard. The photos were only snapshots that showed the status of the Roof at certain points of time. The photos did not demonstrate the work process in its entirety. For instance, Dr Lam relies on a few photos taken on 4^th January 2020[99] to support his criticism that the 4^th Defendants’ workers directly applied waterproofing materials onto the L-shape junctures between the floor and a structure on the Roof (腳線). However, as demonstrated by Mr Siu during cross-examination, the photos[100] that were taken a few minutes afterwards showed that a worker was still in the course demolishing the surface of the L-shape junctures (腳線). Further, although Dr Lam relies on a photo taken on 17^th January 2020 that appears to show that a layer of materials was added onto part of the L-shape junctures, he was not in a position to tell what works were carried out during the period from 4^th January 2020 to 17^th January 2020. These examples demonstrate that Dr Lam does not know and understand the work process adopted by the 4^th Defendant. He could not have known and/or understood the work process based on the photos alone. He could not have come to an informed view without studying, inter alios, the “the photographs at each step of the re-waterproofing works”, the “method statements” and the “materials used”. As Dr Lam tacitly accepted in paragraph 3.7 of his 2^nd supplemental report[101] and expressly conceded during cross-examination, he did not consider these information and/or documents.

(e) Dr Lam also relies on the protimeter readings in Flat 25D to support his conclusion that the 4^th Defendant’s works were defective. This is presumptuous. As will be elaborated below, the high protimeter readings could be ascribed to a number of reasons (such as the defects of the waterproofing membrane in the walls of the Water Tank Houses). It cannot be assumed that the only plausible cause of the high protimeter readings was the alleged defects in the waterproofing system on the floor of the Roof. This kind of “reverse-engineering” analysis is designed to justify the outcome that the 1^st and 2^nd Defendants wishes to achieve. I am not impressed.

(f) For the above reasons, I reject Dr Lam’s assertions and observations.

(2) As regards Ms Lau, like Dr Lam, she did not investigate the materials used by the 4^th Defendant and did not carry out any inspection for the purpose of ascertaining whether the 4^th Defendant’s works were defective and/or sub-standard as alleged. As Ms Lau fairly conceded, she was not in a position to conclude whether there was compatibly issue in respect of the pre-existing materials and the subsequently added materials. In the premises, the observations and assertions set out in her supplemental report dated 15^th September 2023 are speculative and carry no weight at all.

111.  To sum up, although the water seepage in Flat 25D persisted, the evidence does not show that the 4^th Defendant’s works were defective. I reject the assertions that the 4^th Defendant was negligent in carrying out the works under the 2016 Engagement Letter and that the 4^th Defendant’s waterproofing works on the Roof were defective and/or sub-standard.

112.  It is Mr Chiu’s evidence (which I accept) that in light of the persistent water seepage problem, in January 2020 he started to ascertain the cause of the water seepage. On 4^th January 2020, Mr Chiu removed the materials on the surface and the waterproofing membrane at the L-shape juncture between the floor of the Roof and the walls of the Water Tank House that contains the fresh water tank. It was discovered the area was wet and there was water seeping out.

113.  When Mr Chiu gave oral evidence, he pointed out that due to gravity, it was likely to be the case that the water at the L-shape juncture (腳線) came from above, ie the walls of the said Water Tank House. Thus, it could be inferred that the water seepage emanated from the defects in respect of the waterproofing membrane on the walls of the Water Tank House. Although Mr Chiu is not a qualified engineer, his observations, though not conclusive, make sense. After all, Mr Chiu is an experienced technician who deals with all kinds of problems in worksites on a daily basis. As will be elaborated below, Mr Chiu’s observations are consistent with the opinion expressed by Ms Lau (ie the Plaintiffs’ expert).

114.  Similarly, Mr Pang also pointed out that when the 4^th Defendants’ workers removed the concrete and screed on the walls of the Water Tank House containing the fresh water tank and the pump room on 15^th June 2020,[102] it was discovered that there was crystalized liquid that contained rust and white power. When Mr Pang gave oral evidence, he said that from his experience, the substance on the walls was efflorescence (白華) and the same could only be formed after a persistent period of water seepage in an enclosed area. Mr Pang also pointed out that when he inspected the Roof, it was a sunny day, and thus the likely explanation was that there had been persistent water seepage Although Mr Pang’s suggestion is not conclusive, it makes sense.

115.  Mr Chiu said that as early as 17^th January 2020, he informed the 2^nd Defendant’s staff who was responsible for Tower 12A (主任), namely a Mr Mok, about his observations regarding the walls of the Water Tank Houses.

116.  However, it transpired on 8^th April 2020, the 2^nd Defendant issued another demand letter to the 4^th Defendant[103]. As such, Mr Chiu asked his colleagues to draft and issue the letter dated 26^th June 2020[104] to put on record the 4^th Defendant suspected that the source of water leakage was the “upper roof” (高層天台), and the 4^th Defendant would no longer carry out further remedial works. When Mr Chiu testified, he explained that the phrase “upper roof” (高層天台) referred to the structures above the floor on the Roof, including the Water Tank House containing the fresh water tank and the Staircase House that was linked thereto. Mr Chiu’s explanation makes sense, and I accept the same.

117.  For all the above reasons, I am of the view the factual evidence points towards the direction that the water seepage in Flat 25D:-

(1) was not caused by any alleged defect in respect of the waterproofing membrane in the floor and the L-shape junctures (腳線) on the Roof; and

(2) originated from the walls surrounding the Water Tank House that contains the freshwater tank.

118.  In coming to this view, I take into account the following matters:-

(1) It was not inherently likely that all the contractors engaged by the 1^st and 2^nd Defendants throughout the years were incompetent and/or negligent.

(2) It was not inherently likely that all the works carried out the contractors engaged by the 1^st and 2^nd Defendants throughout the years were defective and/or sub-standard.

(3) It was not inherently likely that while all the contractors involved were incompetent and/or negligent and all their works were defective and/or sub-standard, the florescent dye tests that were carried out repeatedly did not reveal any sign of water leakage. In this connection, I take into account that florescent dye tests are not conclusive.

(4) Mr Chiu, who oversaw and supervised the works carried out by the workers engaged by the 4^th Defendant, was responsible and capable. His technical knowledge was sound, and he knew about the details of the works very well. It was unlikely that any apparent defect and/or deviation from usual or required procedures would escape his attention.

(5) Mr Samson Wong, who was a qualified building service engineer, supervised and oversaw the works carried out by the 4^th Defendant on the Roof. Had he taken the view that the 4^th Defendants’ works were defective and/or problematic, he would not have signed the completion form on 27^th March 2020 shortly after a complaint was made on 20^th March 2020. However, I take into account that the said completion form was not concerned with workmanship and that Mr Samson Wong did not testify. As such, the weight attached to this factor is limited.

(6) There is no substance in the Plaintiffs and 1^st and 2^nd Defendants’ assertions that the 4^th Defendant’s works on the Roof were defective and/or negligent. These assertions are not supported by the evidence, and the Plaintiffs and the 1^st and 2^nd Defendants have not been unable to pinpoint what the alleged defect(s) was or were about.

(7) I accept Mr Chiu evidence that after removing the concrete and waterproofing membrane, it was discovered that there was water at the L-shape junctures (腳線) between the floor on the Roof and the bottom of the Water Tank House that contains the fresh water tank. I also agree with Mr Chiu’s observation that due to gravity, it was likely that the seepage came from above (ie the wall of the said Water Tank House), though this observation is not conclusive.

(8) I accept Mr Pang’s evidence that there was crystalized liquid with rust and white power on the walls of the Water Tank House that contains the freshwater tank and the pump room. This was a sign that the waterproofing membranes of these walls might be damaged, though this is not conclusive.

Overview of the Experts’ Opinion

119.  I now analyze the opinion expressed by the parties’ experts.

120.  In gist:-

(1) The Plaintiffs’ expert, ie Ms Lau, opines that the water seepage in Flat 25D originated from (i) the floor on the Roof and the L-shape junctures between the floor and the walls of the structures on the Roof (腳線); (ii) the walls of the Water Tank Houses on the Roof; and (iii) the external walls of Block 12A.

(2) The 1^st and 2^nd Defendants’ expert, ie Dr Eddie Lam, opines that the water seepage in Flat 25D originated from the floor of the Roof and the L-shape junctures (腳線).

(3) Adopting Mr Chung’s opinion, the 4^th Defendant’s expert, ie Mr Hau, opines that it was not shown that the water seepage in Flat 25D originated from the floor and L-shape junctures (腳線) on the Roof and that the walls of the Water Tank Houses on the Roof were a source of water leakage.

121.  Ms Lau, Dr Eddie Lam and Mr Hau (who adopted Mr Chung’s opinion) testified in Court. They were extensively cross-examined by counsel.

The Experts’ Opinion that the Floor on the Roof and the L-shape Junctures (腳線) was a source of the Water Leakage in Flat 25D

122.  I will first deal with the opinion of Ms Lau. As mentioned, she asserts that the waterproofing membrane in the floor and the L-shape junctures (腳線) on the Roof was defective, and this was one of the causes of the water leakage in Flat 25D.

123.  After Ms Lau and her colleagues conducted a fluorescent dye test in early September 2020, they used the following methods to ascertain whether the source of the water leakage was the floor on the Roof and the L-shape junctures (腳線):-

(1) infrared scan;

(2) electric conductivity sensing; and

(3) microwave scan.

124.  Ms Lau accepts that:-

(1) No fluorescent dye test was seen in the ceilings of Flat 25D;

(2) The infrared scan revealed that the moisture level in the ceilings of Flat 25D did not increase significantly or meaningfully after the fluorescent dye test was conducted; and

(3) The electrical conducting sensing revealed that the moisture level in certain areas on the ceiling of the dining room and the ceiling of the living room in Flat 25D did not increase significantly or meaningfully after the fluorescent dye test.

125.  The aforesaid results show that the floor on the Roof and the L-shape junctures were not the source of the water seepage in Flat 25D.

126.  Nonetheless, Ms Lau relies on the following matters in support of her assertion that the water seepage in Flat 25D originated from the floor on the Roof and the L-shape junctures (腳線):-

(1) The electrical conducting sensing revealed that the moisture level in some areas on the ceiling of the dining room and the ceiling of the guest bathroom increased significantly after the fluorescent dye test was conducted. Ms Lau suggests that the increase in moisture in level shows that the water leakage came from the floor and/or the L-shape junctures (腳線) on the Roof; and

(2) The microwave scan revealed that there was a “path” of water (腳線) emanating from the floor on the Roof and/or the L-shape junctures (腳線).

127.  Mr Stephen Siu (for the 4^th Defendant) contends that Ms Lau’s reliance on the outcome of the electrical conducting sensing exercise is misplaced. Mr Siu points out that Mr Chung also conducted a florescent dye test in January/February 2022, and thereupon Mr Chung used the method of electrical conductivity sensing as well as the method of infrared scan to ascertain whether the moisture level in Flat 25D increased. The outcome was that the moisture level did not significantly or meaningfully increase at all.

128.  Ms Lau could not detect any impropriety and/or irregularity as to the way in which Mr Chung conducted the florescent dye test and electrical conductivity sensing.

129.  In the circumstances, why was the result of the tests conducted by Ms Lau (and her colleagues) different from the result of the tests conducted by Mr Chung?

130.  Mr Siu submits that the difference was ascribed to the following reasons:-

(1) First, when Ms Lau and her colleagues conducted fluorescent dye test in early September 2020, the fluorescent dye entered into the floor of the Staircase House on the Roof. Since the waterproofing membrane of the Staircase House was defective, the water or moisture entered the ceilings of the dining room and guest bathroom in Flat 25D. This was why the moisture level there increased.

(2) Second, when Ms Lau’s colleagues collected data in respect of the moisture level at the ceilings of Flat 25D before and after the fluorescent dye test, they did not measure the same locations, and there were discrepancies. Thus, the data collected was not reliable.

131.  For the following reasons, I accept Mr Siu’s submissions on the first reason set out in the paragraph immediately above (ie the fact that fluorescent dye entered the Staircase House on the Roof):-

(1) In her report dated 23^rd October 2020[105], Ms Lau fairly put on record that on 2^nd September 2020, it was discovered that the fluorescent dye somehow penetrated into the Staircase House on the Roof. As evidenced by the photos provided by Ms Lau[106], there was a considerable amount of fluorescent dye on the floor of the Staircase House.

(2) As evidenced by a photo annexed to his report[107], Mr Chung blocked the entrance/exit of the Staircase House. As such, no fluorescent dye could have entered the Staircase House when Mr Chung conducted the fluorescent dye test.

(3) There was obviously a significant difference between the fluorescent dye test conducted by Mr Lau/her colleagues and the fluorescent dye test conducted by Mr Chung. However, Ms Lau disagreed that the increase in moisture level in Flat 25D was ascribed to the fact that fluorescent dye entered into the Staircase House.

(4) When Ms Lau was asked to explain why the outcome of the tests that she and her colleagues conducted was different from the outcome of the tests that Mr Chung conducted, she said that while she and her staff conducted the fluorescent dye test and electrical conductivity scanning in September 2020, Mr Chung conducted the same exercises in January/February 2022, and it was uncertainty as to whether any works were carried out on the Roof during the period from September 2020 to January/February 2022.

(5) Upon hearing Ms Lau’s response, Mr Siu swiftly pointed out that there was no evidence showing that any reparation and/or additional works were carried out on the Roof from September 2020 to January/February 2022.

(6) In these premises, Ms Lau conceded that if the circumstances did not change, the outcome of the tests that she and/or her colleagues carried out and the outcome of the tests that Mr Chung carried out ought to be the same.

(7) Nonetheless, Ms Lau insisted that the increase in moisture could not be ascribed to the fluorescent dye that entered the Staircase House. She said that the Staircase House was far away from Flat 25D and that no florescent dye was seen in any part of Flat 25D.

(8) I am not persuaded by Ms Lau’s explanations.

(9) First of all, as shown by the plans annexed to Ms Lau’s report dated 23^rd October 2020[108], the location of the floor of the Staircase House where the fluorescent dye appeared is not far away from the dining room and guest bathroom of Flat 25D. In any event, as pointed out by Deputy District Judge Simon Ho in Yik Yuen Ling v Tso Wing Yan (supra) at para 122 (citing Building Management in Hong Kong (3^rd Ed) at para 7.30), “water is notoriously able to find conduits to run along and to penetrate weak points some distance from its origin”. I cannot see how Ms Lau could refute the possibility the increase in moisture level was ascribed to the fluorescent dye in the Staircase House.

(10) Second, as pointed out by Ms Lau in her own report, there are various reasons why fluorescent dye does not appear in the ceiling of the subject property despite defects in the waterproofing membrane. For instance, the fluorescent dye could be absorbed or blocked by the materials within the slab. When Ms Lau gave oral evidence, she emphasized that in order to enhance the chance of revealing the fluorescent dye in the ceiling of the subject property, it would be necessary to keep flushing and adding more fluorescent dye in the course of conducting the test. In the present case, the focus was the floor and L-shape junctures (腳線) on the Roof, not the floor side the Staircase House. Thus, understandably, Ms Lau and/or her colleagues would not have kept flushing and/or adding florescent dye inside the Staircase House. It is not even suggested that this was done. In my view, this was a possible (if not likely) explanation as to why although no florescent dye emerged in Flat 25D, the moisture level in various locations increased.

(11) To sum up a material difference between tests carried out by Ms Lau and/or her staff and the tests carried out by Mr Chung was that a considerable amount of florescent dye entered into the Staircase House when Ms Lau and/or her staff carried out the tests. I am of the view that this could be a key contributing factor that caused the moisture level in the ceilings of the dining room and guest bathroom in Flat 25D to increase.

(12) My view is consistent with Mr Pang’s factual evidence and the 1^st Plaintiff’s factual evidence. As mentioned, it is the 1^st Plaintiff’s evidence that there was often serious water seepage shortly after heavy rains. It is also Mr Pang’s evidence that when he attended the Roof in February 2022 on a rainy day, there was a considerable amount of water on the floor inside the Staircase House. The said factual evidence is consistent with and supports Mr Siu’s contention that the floor in the Staircase House was also a source of water leakage.

(13) Taking the totality of the evidence and the objective circumstances into account, I disagree that the increase in moisture level under the tests carried out by Ms Lau and/or her staff supports the assertion that the source of water seepage was the floor of the Roof and/or the L-shape junctures. In my view, it is unsafe for Ms Lau to rely on the result of the electrical conductivity scanning that was conducted after the florescent dye test, and she is not in a position to refute the possibility that the increase of moisture level was ascribed to the florescent dye on the floor of the Staircase House.

132.  For the following reasons, I also accept Mr Siu’s submissions on the second reason (ie inconsistencies in respect of the locations where data was collected):-

(1) In her report dated 23^rd October 2020, Ms Lau set out the spots where her colleagues obtained data in respect of the moisture level in the ceiling of Flat 25D. The photos annexed to the report show that labels were placed in various spots in the ceiling and Ms Lau’s colleague(s) used a protimeter to measure the moisture level in respect of each of these spots. The report also contains tables that set out the data in respect of all these spots.

(2) When Ms Lau was cross-examined, she fairly accepted that the accuracy of the data might be compromised if her colleague(s) did not obtain data from the exact location before the florescent dye test was conducted and after the fluorescent dye test was conducted.

(3) In light of Ms Lau’s concession, Mr Siu, based on the photos annexed to Ms Lau’s report, pointed out that Ms Lau’s colleague(s) did not obtain data at exact locations before and after the fluorescent dye test.

(4) Spot number 40 in the dining room offers a good illustration. The photos[109] reveal that when a colleague of Ms Lau collected data in respect of spot 40 before the fluorescent dye test was conducted, he placed a protimeter on the left-handed side of the label placed on the spot. However, when he/she collected data in respect of spot 40 after the fluorescent dye test was conducted, he/she placed a protimeter on the right-handed side of the same label. The data collected by Ms Lau’s colleague(s) shows that the moisture level at spot 40 increased from 46.1 to 99.9 after the fluorescent dye test was conducted. However, Mr Siu points out that spot 40 was on the left-handed side of spot 46, which had an extremely high level of moisture or humidity both before and after the fluorescent dye was conducted (ie 99.9 out of 100).

(5) In the premises, Mr Siu submits that the moisture level in spot 40 increased drastically because Ms Lau’s colleague moved towards the direction of a spot (ie the spot 46) with extremely high level of moisture or humidity when he/she collected data after the florescent dye test.

(6) To make good his submission, Mr Siu further points out that unlike the way in which data was obtained in regard to spot number 40, the photos[110] show that Ms Lau’s colleague(s) measured almost the exact locations in respect of spots 43, 45, 47, 48 and 50 in the dining room before and after the fluorescent dye test was conducted. This explained why unlike spot 40, the moisture level in respect of these spots did not increase drastically after fluorescent dye test was conducted. The data is as follows[111]:-

Spots	Level of Moisture before Ms Lau’s Fluorescent Dye Test (ie 1st September 2020)	Level of Moisture after Ms Lau’s Fluorescent Dye Test (ie 3rd September 2020)
43	25.2	30
45	40.5	41.2
47	89.4	89.3
48	41.4	43.9
50	24.0	25.2

(7) I see the force of Mr Siu’s submissions. In light of the stark contrast between the situation regarding spot 40 and the situation regarding spot 43, 45, 47, 48 and 50, I agree that the increase in moisture level after the fluorescent dye test could be ascribed to the fact Ms Lai’s colleagues did not obtain data from the exact locations before and after the fluorescent dye test.

(8) For this additional reason, I am of the view that it is unsafe to rely on the outcome of the electrical conductivity sensing conducted by Ms Lau and/or her colleagues.

133.  As regards Ms Lau’s opinion based on the microwave scan:-

(1) Mr Siu extensively cross-examined Ms Lau on the judgments of following cases where she testified as an expert:

(a) Chen Pui Kei Peggy v Cheng Kin Chow & Anor [2024] HKLDT 86 at paras 6, 19, 28, 30, 35 and 53 to 66 (per Deputy District Judge Michelle Lam, as Her Honour Judge Michelle Lam then was);

(b) Polysoon Investments Ltd v Lau Mo Kun & Ors [2022] HKDC 211 at paras 102 to 113 (per His Honour Judge Herbert Au-Yeung, as Herbert Au-Yung J then was); and

(c) Choy Shok Chun v Yu Hon Keung [2022] HKDC 671 at para 102 (per His Honour Judge MK Liu).

(2) In these cases, the Courts rejected Ms Lau’s suggestion that a microwave scan could identify the source of water leakage and/or the “water path (水路)”.

(3) Ms Lau accepted that the microwave scans that she conducted in the aforesaid cases were the same as the exercise that she performed in the present case. She also accepted that the methodology and analysis adopted in the aforesaid cases were the same as the those that she applied in the present case.

(4) I have independently considered Ms Lau’s views and explanations as well as another recent judgment (ie Chau Wai ung & Anor v Lam Tak Chuen & Anor [2024] HKCFI 2013 at paras 69-77) where the Court preferred Ms Lau’s opinion to Mr Chung’s opinion on questions regarding microwave scan.

(5) I prefer and agree with the analysis of Herbert Au-Yeung J, His Honour Judge MK Liu and Her Honour Judge Michelle Lam as elaborated in the judgments mentioned above. In my view, Ms Lau is unable to put forward any compelling answers that address the concerns expressed by these learned judges.

(6) Having considered the opinion expressed by Ms Lau and the analysis set out in the aforesaid judgments, I am of the view that whilst a microwave scan may show whether there is water seepage in the ceiling of the subject property, it is not a reliable method to ascertain whether the water seepage in the property below originates from the property above. I take this view for the following reasons:-

(a) A microwave scan only shows the level of moisture in various locations at the depths of 30mm, 70mm and 110mm from ceiling of the subject property.

(b) A microwave scan does not ipso facto show the vertical or horizontal movement of water.

(c) Since “water is notoriously able to find conduits to run along and to penetrate weak points some distance from its origin” (see Yik Yuen Ling v Tso Wing Yan (supra) at para 122 (citing Building Management in Hong Kong (3^rd Ed) at para 7.30), it cannot be assumed that the water or moisture at a lower depth (say 30mm) necessarily comes from the higher level that was vertically above (say 70mm). It is possible that the water or moisture emanates from an area that has not been scanned at all.

(d) More fundamentally, without knowing the thickness of the slab between the property below and the property above, it cannot be assumed that there is excessive water or moisture at the level above 110mm. Thus, it does not follow that the water seepage (if any) necessarily comes from the floor of the property immediately above. Such assumption is arbitrary.

(7) In my view, depending on the circumstances, it may be worthwhile to conduct microwave scans before and after a fluorescent dye test is carried out as the exercise of identifying and analyzing the changes (if any) may shed some light on the movement of the water or moisture (if any). However, in the present case, Ms Lau did not carry out two rounds of microwave scans before and after she carried out the fluorescent dye test. Thus, it is impossible to conduct a comparison exercise.

(8) As regards the point mentioned in sub-paragraph (6)(d) above, the scenario in the present case is the same as Choy Shok Chun (supra) at para 102. Ms Lau (as well as Dr Lam) suggest that the slap between the ceiling of Flat 25D and the floor of the Roof is 150mm. Since the places above 110mm were not scanned at all, the water or moisture level there was unknown. Without knowing the water or moisture level above the depth of 110mm, I cannot see how Ms Lau could conclude that the water necessarily came from the floor and/or L-shape juncture (腳線) on the Roof. Her conclusion is plainly untenable.

(9) Along the same line of reasoning, I also disagree with Mr Li’s contention that the microwave scan is valuable in showing that the fluorescent dye applied by Ms Lau had stayed in the slaps as there was no rain on 1^st, 2^nd and 3^rd September 2020. This contention is premised on the assumption that the water or moisture within the slap necessarily came from the floor and/or L-shape junctures (腳線) on the Roof. There is no basis to make this assumption at all. It could be the case that the water or moisture (i) came from areas that were not scanned; and/or (ii) was accumulated before the fluorescent dye test was carried out. Without conducting microwave scans (i) before and after the fluorescent dye test; and (ii) before and after heavy rainfall, it is impossible to find out the changes (if any) and carry out a meaningful analysis.

(10) For completeness, I also accept Mr Hau’s opinion that it was not appropriate to conduct a microwave scan in the circumstances of the present case. Mr Hau pointed out that the steel embedment that was exposed and the spalled concrete with rough surface would affect the outcome. Mr Hau was able to explain why the exposed steel embedment and the rough surface would affect the data. It appears to me that there was a sound reason why Mr Chung did not conduct a microwave scan back in January/February 2022.

(11) For the above reasons, I reject Ms Lau’s analysis based on microwave scan, and I disagree with her opinion in this regard.

134.  In the premises, I reject Ms Lau’s opinion that the floor and/or L-shape junctures (腳線) on the Roof was a source of the water seepage in Flat 25D.

135.  I now deal with the opinion expressed by Dr Eddie Lam. He opines that the water seepage came from the area on the Roof that was vertically above Flat 25D, and that there were defects in the waterproofing membrane in the floor and the L-shape junctures (腳線). In his first report dated 26^th February 2022[112] and oral evidence, Dr Lam said that the bases of his opinion were as follows:-

(1) When he inspected Flat 25D back in January 2022, he saw that the ceiling spalled and there were dried-up watermarks. There were also exposed reinforcements and extensive delamination. Whilst he measured the moisture level with a protimeter, he also checked the ceiling by conducting a “tapping test”.

(2) The owners of Flat 25D made repeated complaints for years, and there were repeated attempts to carry out reparation works from 2012 to 2013. It transpired that the 4^th Defendant was engaged to carry out re-roofing works and further reparation works. Before the 4^th Defendant carried out works, the complaints ceased. However, shortly after the 4^th Defendant completed the works, the owners of Flat 25D complained again.

(3) Dr Lam also said that he took into account the contents of Ms Lau’s first report dated 23^rd October 2020.

136.  I reject Dr Lam’s opinion and evidence in their entirety.

137.  Dr Lam has not performed the function expected of an expert. Dr Lam does not put forward any scientific analysis to justify his purported opinion. He effectively argues that since the Plaintiffs had complained about water seepage for years and it appeared that there was water seepage in Flat 25D, the waterproofing membrane in the area that was vertically above Flat 25D must be defective and the 4^th Defendant who was involved in carrying out reparation works must be at fault. This is presumptuous, arbitrary and speculative.

138.  When Dr Lam gave oral evidence, he suddenly mentioned that the fluorescent dye applied by Mr Chung (which was purple in colour) could be seen in the photos in respect of the guest bathroom[113] that were annexed to Ms Lau’s supplemental report dated 6^th May 2022. Dr Lam said that this important matter somehow escaped the attention of all the experts. Although Dr Lam has not inspected Flat 25D after 17^th January 2022, he suggests that the purple marks appearing in the photos show that the fluorescent dye test used by Mr Chung reached the ceiling in the guest bathroom of Flat 25D, and thus the conclusion is that the waterproofing membrane in the floor on the Roof must be defective.

139.  Dr Lam’s belated suggestion is surprising. It was not dealt with anywhere in the joint expert report (“Joint Expert Report”) and not mentioned in any of the reports prepared by the experts. Dr Lam said that he only discovered this allegedly important matter shortly before the present trial took place.

140.  I reject Dr Lam’s belated suggestion:-

(1) The photos that Dr Lam relied on were taken by Ms Lau and/or her colleagues on 21^st February 2022, and the purpose of their inspection was to ascertain the outcome of the fluorescent dye test that Mr Chung conducted in January/February 2022[114].

(2) Had the fluorescent dye test carried out by Mr Chung shown positive result, the same could not have escaped the attention of all the experts (including Ms Lau and Dr Lam himself). In this connection, the Plaintiffs and the 1^st and 2^nd Defendants (who engaged Ms Lau and Dr Lam respectively) were eager to prove that the waterproofing membrane in the floor and/or L-shape junctures (腳線) on the Roof was defective. It is most surprising that this matter was not even discussed in the Joint Expert Report at all.

(3) In any event, Dr Lam’s new allegations are contradicted by the photos and computer records provided by Mr Pang[115], which show that the purple marks on the ceiling of the guest bathroom had already existed before Mr Chung carried out the fluorescent dye test on 19^th January 2022. Whilst Mr Chung carried out the fluorescent dye test at around 4pm in the afternoon on 19^th January 2022, Mr Pang took the photos that showed the existence of the purple marks at around 10:33am on the same day. Thus, the marks (about which Dr Lam took issue) must have nothing to do with Mr Chung’s fluorescent dye test.

141.  Based on the outcomes of the florescent dye test as well as the electrical conductivity scanning and infrared scanning conducted by Mr Chung on 19^th January 2022, 21^st January 2022 and 17^th February 2022, Mr Hau, adopting the data and analysis set out in Mr Chung’s report dated 13^th April 2022, opines that taking into account the fact that the moisture level in Flat 25D did not significantly increase after fluorescent dye test was conducted, it was not shown that the water seepage originated from the floor and L-share junctures (腳線) on the Roof.

142.  Mr Wong (for the 1^st and 2^nd Defendants) criticizes the way in which Mr Chung conducted the fluorescent dye test in January/February 2022. He contends that since Mr Chung did not apply the fluorescent dye up to the level of 500mm (ie the height of the entire L-shape junctures (腳線), he was not in a position to tell whether the L-shape juncture was defective or not. Thus, Mr Hau (who adopted Mr Chung’s data and analysis) is also not in a position to rule out the possibility that the floor and L-share junctures (腳線) on the Roof was a cause of the water seepage.

143.  Mr Wong’s criticism is unmeritorious and unsupported by the evidence from the experts:-

(1) There is not a shred of evidence from the experts suggesting the florescent dye should cover the entirety of the L-shape juncture (腳線) up to the level of 500mm. None of the four experts who have been involved in the present proceedings has suggested that this is the standard required for conducting fluorescent dye tests.

(2) Had Mr Wong’s criticism been valid, this matter would not have escaped the attention of the experts engaged by the Plaintiffs and the 1^st and 2^nd Defendants. For obvious reasons, neither Ms Lau nor Dr Eddie Lam suggests that the fluorescent dye test carried out by Dr Chung in January/February 2022 was problematic, flawed and/or not up to standard.

(3) I accept Mr Hau’s evidence that the standard was such that the fluorescent dye should reach the level of 20mm only. I also accept Mr Hau’s observation that based on the images in photos (which are incontrovertible), the fluorescent dye applied by Mr Chung reached the level of 20mm. Mr Hau’s evidence is consistent with the fact that neither Ms Lau nor Dr Eddie Lam criticized or commented on the fluorescent dye test carried out by Mr Chung.

(4) Indeed, the photos annexed to Ms Lau’s first report dated 23^rd October 2020[116] show that the fluorescent dye that she and/or her colleagues applied was far from the top of the L-shape junctures (ie 500mm above the floor). According to Ms. Lau whose evidence is neither challenged nor disputed, the fluorescent dye that she applied only reached the level of 2-inches (ie about 50mm).

(5) Although Mr Wong was critical of Mr Chung, he did not challenge or criticize Ms Lau at all. The reason was obvious. Whilst Mr Chung’s opinion contradicts the 1^st and 2^nd Defendants’ case, Ms Lau’s opinion supports the 1^st and 2^nd Defendants’ case.

(6) I cannot see how Mr Wong can seek to have the best of both worlds when neither Mr Chung nor Ms Lau applied fluorescent dye to cover the entire L-shape junctures (腳線) up to 500mm. Mr Wong’s approaches to the 2 sets of experts’ evidence are inconsistent, and his contention has no merits.

(7) In this connection, Mr. Wong argues that whilst Mr. Chung merely said it could not be shown that the floor and L-shape junctures (腳線) were a cause of the water seepage, Ms. Lau affirmatively asserts that the floor and the L-shape junctures (腳線) were a cause of the water seepage. What Mr. Wong seeks to do is to draw a distinction without a difference and then makes a song and dance about it. This is unhelpful.

(8) The most important matter that the two experts took into account was whether the moisture level in Flat 25D increased after the fluorescent dye test. Since the moisture level in certain spots in Flat 25D increased after her tests, Ms. Lau opined that the floor and the L-shape junctures (腳線) were a cause of the water leakage. However, under the tests conducted by Mr. Chung, the moisture level in Flat 25D did not significantly increase. Thus, he opined it could not be shown that the floor and the L-shape junctures (腳線) were a cause of the water leakage. The crux is whether the moisture level increased or not and the reason(s) that explained the change (ie the outcome of Ms. Lau’s test) and the absence of change (ie the outcome of Mr. Chung’s test). Mr. Wong does not have an answer at all.

(9) In any event, as pointed out in paragraph 7.6.1 of his report dated 13^th April 2022[117], Mr Chung on purpose flushed and splashed fluorescent dye onto areas with cracks in the L-shape junctures (腳線). In my view, there is no room to criticize Mr Chung for overlooking the L-shape junctures (腳線).

144.  Mr Li (for the Plaintiffs) points out that in his report dated 13^th April 2022, Mr Chung did not (i) criticize the way in which Ms Lau and/or her colleagues conducted the tests in September 2020; and (ii) rebut Ms Lau’s conclusion in her report dated 23^rd October 2020. Mr Li then goes on to contend that Mr Hau (who adopted Mr Chung’s report) has no basis to disagree with Ms Lau’s conclusion that the water seepage originated from the floor and L-shape junctures (腳線) on the Roof as Mr Chung agreed with Ms Lau’s data and analysis.

145.  There is neither substance nor merit in Mr Li’s contention:-

(1) Since Mr Chung had no personal knowledge as to how Ms Lau and/or her colleagues conducted the tests in September 2020, it is understandable why Mr Chung did not raise criticism or comment in respect thereof.

(2) Whilst Mr Chung did not criticize Ms Lau, it does not mean that he agreed with Ms Lau’s views and analysis.

(3) In his report dated 13^th April 2022, Mr Chung clearly set out the data arising from the tests that he conducted in January/February. Mr Chung explained why he took the view it could not be shown that the floor and L-shape junctures (腳線) on the Roof were not a source of water leakage. One of the important matters that Mr Chung took into account was that there was no significant change in the moisture level before and after the fluorescent dye test[118].

(4) It is plain that Mr Chung disagreed with Ms Lau’s views. I cannot see how Mr Li could put words into Mr Chung’s mouth by suggesting he agreed with Ms Lau’s analysis in September/October 2020. This suggestion is neither true nor logical.

146.  Similar to the contention raised by Mr Siu as elaborated in paragraph 132 above, Mr Li points out the photos annexed to Dr Chung’s report dated 22^nd April 2022 show that there were inconsistencies in respect of the locations from which data was collected before and after the fluorescent dye test was conducted. In particular, Mr Li takes issues about the locations in respect of spots 2, 4, 5, 34, 39, 42, 45, 47 and 53. He contends that Mr Chung’s data in respect of the moisture level is not reliable.

147.  I see the basis of Mr Li’s criticism. However, for the following reasons, I am not of the view that the data arising from the test conducted by Mr Chung was flawed and/or unreliable and that Mr Chung’s analysis (which was adopted by Mr Hau) should be rejected:-

(1) Like Ms Lau, Mr Hau also fairly conceded that if there were inconsistencies in respect of the locations from which the data was collected, the data would be affected.

(2) However, Mr Hau made an important point that the exercise of studying and analyzing the data is a qualitative one, and it involves judgment. In particular, the exercise is not merely about mechanically identifying whether the moisture level at certain spots increases or decreases. Instead, it is about identifying a “trend” that is capable of being explained scientifically.

(3) Mr Hau’s explanation makes sense to me.

(4) Mr Siu is able to identify the “trend” in respect of the changes in the data collected by Ms Lau’s colleagues when there were inconsistencies in respect of the location, and he puts forward a scientific explanation that makes sense. As pointed out in paragraph 132(4)-(7) above, the moisture level in spot 40 in the dining room increased because after the fluorescent dye test was carried out, Ms Lau’s colleagues moved towards spot 46 which had an exceptionally high moisture level (ie 99 out of 100). In contrast, when the locations from which data was collected before and after the fluorescent dye test remained the same (eg spots 43, 45, 47, 48 and 50), the moisture level did not increase significantly. By comparing the two sets of data, it can be seen that the increase in moisture level was likely to be related to the fact that data was collected from a location with higher moisture level after the fluorescent dye test. A “trend” is identified, and a scientific explanation is provided.

(5) As regards the data adopted by Mr Chung, Mr Li is only able to point out that insofar as spots 2, 4, 5, 34, 39, 42, 45, 47 and 53 are concerned, Mr Chung and/or his assistant did not place the protimeter at the exact locations before and after the fluorescent dye test. Mr Li points out that sometime the protimeter was placed on the right-handed side of the labels and sometime it was placed on the left-handed side of the labels.

(6) Despite his efforts, Mr Li is unable to identify any “trend” at all. He cannot explain how the data collected by Mr Chung was affected by the slight inconsistencies in respect of the locations from which data was obtained. There is no analysis of the data. There is no analysis in respect of the absence of significant change in the moisture level before and after the fluorescent dye test. Mr Li cannot explain why the data did not change significantly. He cannot put forward a scientific reason to show that the moisture level did not increase significantly because Mr Chung and/or his assistant(s) did not measure the exact locations.

(7) It is easy for legal representatives to pick up an imperfection and then make a song and dance about it. What is difficult is to identify a trend from the data and then put forward a sensible scientific explanation that supports a case theory.

(8) Another valid point that Mr Hau made was that if the spot in question is wet or has a high moisture level, the inconsistency in respect of the location from which data is obtained would have a huge impact. In contrast, if the spot in question is dry or has a low moisture level, the inconsistency in respect of the location from which data is obtained would have limited impact. This explanation makes sense. Unlike spot 40 in the tests conducted by Ms Lau, all the spots identified by Mr Li in the tests by Mr Chung (ie spots 2, 4, 5, 34, 39, 42, 45, 47 and 53) were dry and had low moisture level. It is hardly surprising that Mr Li could identify a trend and could not come up with a scientific reason to explain why the data did not change significantly. This is consistent with the views expressed by Mr Hau (which I accept).

(9) For all the above reasons, I am not of the view that Mr Li has shown that the test conducted by Mr Chung was flawed and that the data that he and/or his assistant(s) collected was unreliable.

148.  For the reasons elaborated above, I am of the view that on proper analysis, the experts’ evidence show that the water seepage in Flat 25D did not originate from the floor and/or L-shape junctures (腳線) on the Roof. In coming to this view, I take into account that:-

(1) The fluorescent dye test conducted by Ms Lau and/or her colleagues did not reveal water leakage.

(2) The fluorescent dye tests conducted by Mr Chung did not reveal water leakage.

(3) The infrared scan conducted by Ms Lau and/or her colleagues revealed that the moisture level in the ceiling of Flat 25D did not increase significantly or meaningfully after the fluorescent dye test.

(4) The electrical conducting sensing conducted by Ms Lau and/or her colleagues revealed that the moisture level in certain areas on the ceiling of the living room and the ceiling of the dining room in Flat 25D did not increase significantly or meaningfully after the fluorescent dye test.

(5) The infrared scan conducted by Mr Chung revealed that the moisture level in the ceiling of Flat 25D did not increase significantly or meaningfully after the fluorescent dye test.

(6) The electrical conducting sensing conducted by Mr Chung revealed that the moisture level in ceiling of the dining room in Flat 25D did not increase significantly or meaningfully after the fluorescent dye test, and I disagree that test conducted by Mr Chung was flawed and/or unreliable.

(7) Ms Lau’s reliance on the partial positive outcome of the electrical conducting sensing that she and/or her colleagues conducted after the fluorescent dye test is misplaced and unsafe. It was likely that the increase in moisture level in part of the ceiling of the dining room and the ceiling of the guest bathroom was ascribed to (i) the fact that the fluorescent dye entered the Staircase House on the Roof; and/or (ii) the fact that Ms Lau’s colleagues did not measure the exact locations in respect of the spots from which data was obtained.

(8) The microwave scan conducted by Ms Lau does not show, and is incapable of showing, that the water seepage originated from the floor and L-shape junctures (腳線) on the Roof.

(9) Dr Lam’s opinion is not supported by any meaningful analysis and is wholly unreliable.

149.  The cumulative effect of the abovementioned negative results speaks volumes. It could not be a sheer coincidence that all these tests revealed negative results.

150.  Insofar as the partial positive result in respect of the electrical conducting sensing conducted by Ms Lau is concerned, Mr Siu is able to demonstrate why the data that she relied on was unreliable. As regards the purported positive result in respect of the microwave scan conducted by Ms Lau, I am of the view that the methodology is unconvincing, and the underlying assumptions are speculative. I am not of the view that there is valid scientific basis to justify the assertion that the water seepage came from the floor and L-shape junctures (腳線) on the Roof.

151.  Put it simply:-

(1) There are consistent valid and reliable negative results showing that the water seepage did not originate from the floor and L-shape junctures (腳線) on the Roof; and

(2) There is no valid or reliable positive result showing that water seepage originated from the floor and L-shape junctures (腳線) on the Roof.

The Experts’ Opinion that the Walls of the Water Tank House were a source of the Water Leakage in Flat 25D

152.  Ms Lau opines that the defects and/or damage in respect of the waterproofing membrane in the walls surrounding the Water Tank Houses were a source of the water seepage in Flat 25D.

153.  As mentioned, Ms Lau and her colleagues attended Flat 25D and the Roof on 1^st, 2^nd, 3^rd and 22^nd September 2022. Unlike 1^st, 2^nd and 3^rd September 2022, 22^nd September 2022 was a rainy day. As such, Ms Lau and her colleagues took the opportunity to obtain data on this occasion such that they could study the impact and/or implications of the rainfall.

154.  The electrical conductivity scanning conducted by Ms Lan and her colleagues revealed that the level of moisture and humidity in Flat 25D increased drastically.

(1) The following table shows the increase in moisture level in certain salient spots on the ceiling of the dining room and living room of Flat 25D[119]:-

Spots	Level of Moisture on 3rd September 2020 (no rain)	Level of Moisture on 22nd September 2020 (heavy rain)
2	27.6	40.3
4	40.8	63.8
5	44.8	65.9
6	25.2	40.4
31	30.2	44
32	66	73.9
41	26.4	47.2
42	52.2	99.9
48	43.9	99.9
50	25.2	39.3

(2) The following table shows the increase in moisture level in certain salient spots on the ceiling of the guest bathroom in Flat 25D[120]:-

Spots	Level of Moisture on 3rd September 2020 (with no rain)	Level of Moisture on 22nd September 2020 (with heavy rain)
1	32.7	45
2	27	41.6
3	25.8	35.6
5	28.4	37.2
8	32.2	40.3
13	40.5	47.2
15	28.5	36
18	26.7	36.4

155.  Why did the moisture level increase in such a drastic manner after the rain?

156.  In my view, the comparison exercise conducted by Ms Lau is meaningful and helpful. It does shed light on the source of the water leakage. I accept Ms Lau’s opinion and analysis that the drastic increase in moisture level was ascribed to the defects and/or damage in respect of the waterproofing membrane in the walls or surface of the Water Tank Houses.

157.  As pointed out by Ms Lau, the rainwater would enter and/or penetrate the damaged parts (if any) of the waterproofing membrane in the walls of the Water Tank Houses. Further, the rain accumulated on the floor of the Roof could not be higher than the level of fluorescent dye that was accumulated when the fluorescent dye tests were conducted. This was because the open drain on the Roof would channel away the rainwater. Thus, the rainwater on the floor would not have an impact on the “test” based on the heavy rainfall. In any event, for the reasons elaborated in paragraphs 122 to 151 above, I find that the water seepage did not originate from the floor and L-shape junctures (腳線) on the Roof, and the suggestion that the waterproofing membrane therein was defective can be excluded.

158.  In the premises, I agree that the drastic increase in moisture level on 22^nd September 2020 was ascribed to the defects in respect of waterproofing membrane in the walls of the Water Tank Houses (and plausibly the Staircase House). This was the most likely explanation.

159.  Dr Eddie Lam cannot explain why the moisture level increased drastically on 22^nd September 2020 when there was heavy rain. He does not have an answer. He cannot meaningfully pinpoint any fallacy of the aforesaid analysis. He cannot detect any flaw or irregularity in respect of the way in which Ms Lau and her colleagues carried out tests and/or collected data on 22^nd September 2020.

160.  While Dr Eddie Lam does not provide any meaningful analysis, Mr Wong criticizes Ms Lau for not taking photos of the walls of the Water Tan Houses and not conducting spray test. The criticism has no substance. The matters identified by Mr Wong have utterly nothing to do with the analysis in respect of the data that was collected on 22^nd September 2022.

161.  I do not lose sight that in Mr Chung’s first report dated 13^th April 2022, it was suggested there was no evidence or sign showing that the water leakage was due to the walls or surface of the Water Tank Houses. However, Mr Chung did not undergo the exercise carried out by Ms Lau. He did not even seek to ascertain whether the moisture level in Flat 25D increased after a heavy rain. Without going through the same exercise, Mr Chung and Mr Hau (who adopted Mr Chung’s opinion), of course, did not share Ms Lau’s views. However, this does not cast doubt on Ms Lau’s analysis (which is sound in my view).

162.  For the above reasons, I am of the view that on proper analysis, the experts’ evidence amply supports the conclusion that the water seepage in Flat 25D was caused by and/or ascribed to the defects in respect of waterproofing membrane in the walls or surface of the Water Tank Houses.

163.  This view is consistent with:-

(1) The aforesaid analysis that the floor and L-shape junctures on the Roof was not a source of water seepage;

(2) The fact that throughout the years, water seepage often occurred after rains;

(3) The fact that the water seepage in Flat 25D recurred throughout the years, despite repeated attempts by different contractors to repair the floor and L-shape junctures (腳線) on the Roof;

(4) The inherent unlikelihood that all the contractors engaged by the 1^st and 2^nd Defendants were incompetent and that all the works that these contractors carried out throughout the years were defective and/or sub-standard;

(5) The fact that the Plaintiffs and the 1^st and 2^nd Defendants have been unable to pinpoint and/or identify any defect in respect of the works carried out by the 4^th Defendant;

(6) The fact that the fluorescent dye tests conducted by the contractors and the parties’ experts throughout the years did not reveal water leakage;

(7) The inherent unlikelihood that whilst all the works carried out by the contractors throughout the years were defective and/or sub-standard, the fluorescent dye tests that were repeatedly carried out did not reveal any water leakage;

(8) The fact that the Water Tank House containing the fresh water tank was almost immediately above Flat 25D;

(9) Mr Chiu’s evidence and observations regarding the situation of the L-shape junctures (腳線) between the floor and the walls of the Water Tank Housese: see paragraph 113 above;

(10) Mr Pang’s evidence and observations regarding the walls of the Water Tank House: see paragraph 114 above; and

(11) Ms Lau’s observations that the walls of the Water Tank House were damaged[121].

The Experts’ Opinion that the External Walls were a source of the Water Leakage in Flat 25D

164.  Arguably, the aforesaid analysis regarding the increase in moisture level also applies to the suggestion that the defects and/or damage in relation to the external walls of Block 12A were also a source of the water leakage in Flat 25D.

165.  However, in light of the following matters, I hesitate to conclude that the water leakage also originated from the external walls of Block 12A.

166.  First, the Global Generation Report did not recommend that the external wall of the Block 12A be repaired. Without any evidence from the representative(s) of Global Generation, the methodologies and approaches adopted by Global Generation are unknown. However, bearing in mind that the context in which the Global Generation Report came into existence, there is every reason to believe that Global Generation would prudently include all plausible reasons that caused the water leakage in Flat 25D. Had Global General taken the view there was, to say the least, a possibility that the external wall of Block 12A was one of the plausible reasons of the water leakage in Flat 25D, it would have recommended that reparation works been done in relation thereto. This was not the case.

167.  Second, Ms Lau and her colleagues used the method of infrared scan to ascertain whether there were damage or defects relating to the external walls around and above Flat 25D. No damage or defects were found[122].

168.  Third, neither Mr Chiu nor Mr Pang observed that condition of the external walls around or above Flat 25D was unsatisfactory and that there was sign of water leakage. They did not detect any reason showing that the water leakage might have anything to do with the external walls of Block 12A.

169.  Taking into the aforesaid matters and all the relevant circumstances, I am, on the available evidence, not satisfied it is proved that the water leakage in Flat 25D was ascribed to any defect and/or damage in relation to the external walls of Block 12A.

Conclusion on the Source of Water Leakage in Flat 25D

170.  My analysis of the experts’ evidence is consistent with (and indeed corroborated by) the factual findings and inherent probabilities discussed in paragraphs 91 to 118 above.

171.  Having carefully considered and analyzed the factual evidence, the inherent probabilities, the objective circumstances and the experts’ evidence, my findings and conclusion are as follows:-

(1) The floor on the Roof and the L-shape junctures (腳線) that connected the floor and the structures on the Roof were not the source of the water leakage in Flat 25D. There was no defect in respect of the waterproofing works carried out by the 4^th Defendant.

(2) The defects of and/or damage to the waterproofing membrane in the walls or surface of the Water Tank Houses were the source of the water leakage in Flat 25D.

(3) It was possible that the floor on the Staircase House was also a source of the water leakage in Flat 25D. However, since the increase in moisture level under the tests carried out by Ms. Lau and/or her colleagues could be caused by (or partially caused by) the inconsistencies in respect of the locations from which data was collected (see paragraph 132 above), I am unable to conclude it is more likely than not that this was the case.

(4) On the evidence before me, I am unable to conclude it is more likely than not that the external walls of Block 12A were a source of the water leakage in Flat 25D.

E3. The Plaintiffs’ Claims against the 1^st and 2^nd Defendants

Nuisance

172.  In Section E1 above, I find that the water seepage in Flat 25D caused physical damage to Flat 25D and seriously interfered with the use and enjoyment of Flat 25D. There is no question that the water seepage constituted nuisance: see eg 張秀玲 訴 鄭禮莊 (supra) at para 26 (per Liu JA).

173.  In Section E2 above, I find that the water seepage originated from the walls of the Water Tank Houses.

174.  It is not in dispute that the Water Tank Houses (and the walls thereof) are common parts of Provident Centre. They were at all material times managed and controlled by the 1^st and 2^nd Defendants, and the same did not fall within the 4^th Defendant’s scope of works under the 2016 Engagement Letter.

175.  In the premises, the crucial issue to resolve is whether the 1^st and 2^nd Defendants took reasonable steps to abate or nullify the nuisance within a reasonable time after they had actual or constructive knowledge in respect thereof: Sedleigh-Denfield v O'Callagan & ors (supra) at pp. 904 to 905 (per Lord Wright) and pp.894-895 (per Viscount Maugham); Leakey & ors v National Trust for Places of Historic Interest or Natural Beauty (supra) at pp 517-518 (per Megaw LJ); and Loke Yuen Jean Tak Alice v Wong Kit Ying & Ors (supra) at para 55 (per Marlene Ng J).

176.  Curiously, the 1^st and 2^nd Defendants’ witnesses had minimal involvement in the events and matters relating to the water seepage in Flat 25D and the works that were carried out on the Roof:-

(1) Whilst Mr Poon Hung (潘雄威) (hereinafter “Mr Poon”) is the current chairman of the 1^st Defendant’s management committee, he only assumed office after this action was commenced.

(2) Madame Chan Miu Nan (陳妙蘭) (hereinafter “Madame Chan”) was the secretary of the 1^st Defendant’s management committee, but she no longer held such position at the time when she testified.

(3) Mr Leung, who testified on the 2^nd Defendant’s behalf, only assumed the position of assistant general manager in December 2022. He was not involved in the day-to-day management of Provident Centre, and he did not have personal knowledge of the matters relating to the present dispute.

177.  Like Mr Leung, Mr Poon and Madame Chan had minimal personal involvement in the matters relating to the present dispute. They told me that the members of the 1^st Defendant’s management committee were volunteers and most of them had full-time jobs. As such, they heftily relied on the 2^nd Defendant’s staff to deal with the matters relating to the Roof and the water seepage in Flat 25D and to report the progress to them.

178.  Having heard their evidence, I am of the view that both Mr Poon and Madame Chan are honest witnesses and respectable individuals who wish to serve their neighbours in good faith. For instance:-

(1) As evidenced by the minutes in respect of the meetings of the 1^st Defendant’s management committee on 11^th May 2022[123], Madame Chan expressed concern as to the delay in carrying out reparation works on the Roof, and she complained that such delay would cause further loss and damage to the owners of Flat 25D.

(2) As evidenced by the minutes of the meeting on 20^th October 2021[124] and 28^th June 2022[125], Mr Poon was concerned about the safety and interest of the owners who were affected by water seepage. Out of safety concern, Mr Poon proposed that the owners of Flat 25C (which was adjacent to Flat 25D) should move out tentatively. Mr Poon also proposed some interim measures to alleviate the condition of Flat 25D, but (as will be elaborated) a representative of the insurance broker who was concerned about preserving evidence suggested that Mr. Poon’s proposal was not advisable.

179.  Despite the bona fides on the part of some of the individual members of the 1^st Defendant’s management committee, I am of the view that the 1^st Defendant, as an entity, and the 2^nd Defendant, as a professional manager, failed to discharge their duties to take reasonable steps to abate the nuisance in a reasonable and timely manner.

180.  I remind myself to take into account the difficulties faced by the 1^st and 2^nd Defendants. I also remind myself not to adopt a critical approach with the benefit of hindsight.

181.  For the reasons elaborated below, I have come to the inevitable conclusion that the 1^st and 2^nd Defendants failed to take reasonable steps to identify the source and reason of the water leakage and to abate the water seepage. They blindly and unreasonably put the blame on the 4^th Defendant. Being influenced by the views expressed by the representative of an insurance broker, the 1^st Defendant took no remedial action on purpose and the reason was to preserve and gather evidence that proved the 4^th Defendant’s negligence (which never emerged). The attitude of the 1^st and 2^nd Defendants was regrettable, and the prolonged delay was unacceptable.

182.  The documents of the 2016 Tender show that back in 2016, the 1^st Defendant envisaged that apart from the floor and the L-shape junctures (腳線), the structures on Roof (including the Water Tank Houses) would be repaired as well. Bearing in mind the age of Provident Centre, this was hardly surprising. If structures on the Roof were in good condition at the time, it was unlikely that the 2016 Tender would cover the same.

183.  It transpired that the 1^st Defendant only repaired the floor and L-shape junctures on the Roof (腳線): see the 2016 Engagement Letter[126]. The 1^st Defendant chose not to repair, inter alios, the waterproofing membrane in the walls of the structures on the Roof, including the Water Tank Houses. Whilst the 2016 Tender consisted of 12 items of works, the 1^st Defendant opted to carry out 3 items of works only. The most probable explanation was that the 1^st Defendant wished to save costs. When Mr Poon testified, he said that the 1^st Defendant had a lot of matters to handle, and there were other individual units in Provident Centre that were affected by water seepage as well.

184.  There was nothing wrong with adopting a prudent approach to expenditure. What was problematic was that from March 2020 onwards, the 1^st Defendant (as well as the 2^nd Defendant) had acted as if the only plausible cause of the water seepage was that the 4^th Defendant negligently carried out the waterproofing works on the floor of the Roof. They conveniently turned a blind eye to fact that only part of the Roof was repaired pursuant to the 2016 Engagement Letter.

185.  It is hard to understand why the 1^st and 2^nd Defendants took no steps to ascertain whether the water seepage could be caused by other factors, such as the defects in the structures erected on the Roof (including the Water Tank Houses). First of all, notwithstanding the Plaintiffs’ complaint on 20^th March 2020, Mr Samson Wong signed the completion form 7 days later on 27^th March 2020. This was, to say the least, prima facie evidence that the 4^th Defendant duly completed the works under the 2016 Engagement Letter. Second, the fluorescent dye test that was carried out in February 2018 did not show any sign of water leakage. Although the fluorescent dye test was not conclusive, it at least supported the conclusion that the water leakage in Flat 25D had nothing to do with the floor and the L-shape junctures (腳線). Third, the structures on the Roof (such as the Water Tank Houses) had obviously aged, and this was the most probable reason why the 2016 Tender covered them. There was nothing unusual about the fact that the waterproofing membrane in these structures had degenerated and/or no longer fully functioned due to wear and tear. Fourth, the Water Tank House that contained the freshwater tank was almost immediately above Flat 25D.

186.  In the circumstances, I cannot see how the 1^st and 2^nd Defendants could simply assume that the 4^th Defendant did not properly perform his contractual duties under the 2016 Engagement Letter and that the water seepage in Flat 25D must be caused by the 4^th Defendant’s breach of duties and/or negligence. This assumption was neither reasonable nor justifiable. The 1^st and 2^nd Defendants knew that the 4^th Defendant was only engaged to repair the floor and the L-shape junctures (腳線) on the Roof, and other parts of the Roof (including the structures thereon) had not been repaired and had nothing to do with the 4^th Defendant.

187.  As pointed out in paragraphs 33 and 80(1) above, during period from 8^th June 2018 to 8^th April 2020, the 1^st and 2^nd Defendants issued no less than 5 demand letters to pressurize the 4^th Defendant to resolve the water leakage problem. Apart from issuing these demand letters to the 4^th Defendant, there is no evidence showing that the 1^st and 2^nd Defendants did anything to find out the cause of the water seepage during this period of time.

188.  Since the 4^th Defendant provided a 5-year warranty pursuant to the 2016 Engagement Letter, the 1^st and 2^nd Defendants might think that it would be convenient to shift the responsibilities to the 4^th Defendant. The submissions that Mr Wong advances on behalf of the 1^st and 2^nd Defendants reflect this misconception. When Mr Wong made oral opening submissions, he emphasized that so long as the 1^st and 2^nd Defendants acted reasonably in engaging, supervising and giving instructions to the 4^th Defendant, they could not be held liable.

189.  This assertion is wrong both on the facts and the law:-

(1) On the facts of the present case, there is no room for the 1^st and 2^nd Defendants to shift the responsibilities to the 4^th Defendant as the warranty that he gave pursuant to the 2016 Engagement Letter only applied to the works that he carried out. The defects and/or damage relating to the Water Tank Houses fell outside of the scope of the 2016 Engagement Letter and had nothing to do with the 4^th Defendant. Thus, the 4^th Defendant was not contractually obliged to deal with and/or find out the defects in relation to the walls of the Water Tank Houses.

(2) Insofar as the law is concerned, in Leung Tsang Hung v IO of Kwok Wing House (supra) at para 25, Ribeiro PJ held that a defendant’s duty to nullify nuisance is “non-delegable”, though it is not strict or absolute. As pointed out in paragraphs 67 to 69 above, there is no valid basis to suggest that Ribeiro PJ’s dictum is inapplicable to private nuisance, which is a legal wrong and which will cause financial loss, discomfort, inconvenience, serious physical injury or even death to innocent parties. Mr Wong did not advance any argument to rebut this analysis. Instead, in his closing submissions, Mr Wong fairly accepted that if a defendant knows or ought to know that his conduct will harm his neighbour, he is under a duty of care to prevent the harm, and in this sense the legal principles on nuisance and the legal principles on negligence coincide. In my view, this concession is rightly made.

(3) In any event, having said that the cause of the water seepage was the walls of the Water Tank House (which were outside of the 4^th Defendant’s contractual duties), on the facts of the present case, Mr Wong’s contention that the 1^st and 2^nd Defendant would not be liable if they reasonably engaged/supervised/instructed the 4^th Defendant is neither here nor there.

190.  On the 1^st and 2^nd Defendants’ case, they confirmed that there was water seepage in Flat 25D after an inspection took place on 8^th June 2018. In light of the circumstances discussed above, as soon as the 1^st and 2^nd Defendants confirmed the existence of the water leakage on 8^th June 2018, they should have started taking steps to ascertain the cause. Instead of blindingly assuming that the 4^th Defendant’s works were defective and that the water seepage must be ascribed to the floor and L-shape junctures (腳線) on the Roof, the 1^st and 2^nd Defendants should have taken steps to ascertain whether the water seepage was ascribed to the areas that were not covered by the reparation works that were done pursuant to the 2016 Engagement Letter. Since the water seepage had been recurring for years, it was not difficult to appreciate the possibility that the water seepage might originate from an area that had not been repaired. This is just a matter of common sense. The 1^st and 2^nd Defendants could not turn a blind eye to an obvious possibility.

191.  Bearing in mind the chequered history and the matters mentioned in paragraph 185 above, the 1^st and 2^nd Defendant should have engaged an independent surveyor as early as possible. Had a reasonable surveyor been appointed promptly, the 1^st and 2^nd Defendant would have known much earlier that (i) it was necessary to repair the waterproofing membranes in the walls of the structures (including the Water Tank Houses) on the Roof; and (ii) the defects there were a cause of the water seepage in Flat 25D.

192.  In the premises, the 1^st and 2^nd Defendants must have constructive knowledge that the water seepage originated from the walls of the Water Tank Houses (which had not been repaired under the works carried out pursuant to the 2016 Engagement Letter). The 1^st and 2^nd Defendants plainly failed to conduct the enquiry that a reasonable IO and a reasonable manager would have conducted in the circumstances. Had due diligence been exercised, they would have discovered the matters mentioned in the paragraph immediately hereinabove. See 張秀玲 訴 鄭禮莊 (supra) at para 26 (per Liu JA); Lau Sin Yee v The Financial Secretary Incorporated (DCCJ 311/2007, 14^th February 2008) at para 11 (per HH Judge Mimmie Chan (as Mimmie Chan J then was).

193.  Whilst Mr Leung recalled that the 1^st and 2^nd Defendants did not appoint Global Generation until August 2022, Mr Wong suggested that Global Generation conducted a site inspection in July 2022. This was more than 4 years after the 1^st and 2^nd Defendants confirmed the water seepage in June 2018. The delay was inordinate and inexcusable.

194.  In my view, even without engaging an independent advisor, the 1^st and 2^nd Defendants should have known that the walls of the Water Tank Houses were likely to be a cause of the water seepage. In this connection, the following matters were notable.

(1) On 18^th November 2020, the Plaintiffs, through solicitors, provided Ms Lau’s first report dated 23^rd October 2020 to the 1^st and 2^nd Defendants[127]. In her report, Ms Lau explained why she took the view that the walls of the Water Tank Houses were a cause of the water seepage. Her analysis and methodologies were explained in detail.

(2) However, there is no evidence showing that the 1^st and/or 2^nd Defendants had studied and/or considered Ms Lau’s reported before the present action was commenced. It is unthinkable as to how the 1^st and 2^nd Defendants could ignore the report. This was irresponsible and unreasonable.

(3) Further, while Mr Chiu orally informed the 2^nd Defendant’s officer (主任) who was responsible for Tower 12A (ie Mr Mok) about his observations regarding the walls of the Water Tank House on 17^th January 2020 (see paragraph 115 above), by the letter dated 26^th June 2020[128] the 4^th Defendant formally informed the 1^st Defendant that the suspected source of water seepage was the structures above the floor on the Roof, including the Water Tank House (see paragraph 116 above).

(4) Mr Poon frankly informed me that some members of the 1^st Defendant’s management committee adopted a dismissive attitude towards the 4^th Defendant’s letter dated 26^th June 2020 as they took the view that the 4^th Defendant only had a “suspicion”. This kind of attitude was irresponsible[129]. The 1^st Defendant should not turn a blind eye to the views expressed by its own contractor. They should have taken follow up action immediately. The inaction was plainly inexcusable.

195.  As evidenced by the contents of the minutes in respect of the meetings of the 1^st Defendant’s management committee on 18^th August 2021[130], 20^th October 2021[131] and 1^st December 2021[132], a Mr Chan Chuek Fan (陳卓勳), who represented an insurance broker named Willis Hong Kong Ltd (“Willis”), repeatedly advised the 1^st and 2^nd Defendants not to carry out reparation works on the Roof as the evidence that sheds light on the question of liability might be affected. Mr. Chan said that if reparation works were carried out, the insurer would not accept their insurance claims. In the meeting on 28^th June 2022[133], Mr Chan even said that in light of the Plaintiffs’ claims in the present action, it was not desirable to adopt the interim protective measure proposed by Mr Poon until all the tests were completed; otherwise, the evidence on the Roof might be destroyed. It appeared that the concern of Mr Chan was to preserve potential evidence that might shed light on the 4^th Defendant’s negligence and/or breach of duties, such that hopefully the insurer might not need to bear the loss at the end of the day[134].

196.  Whilst the priority of the insurer and/or the insurance broker was to preserve and locate evidence showing that the 4^th Defendant was at fault (which never emerged), the priority of the 1^st and 2^nd Defendant was to ensure that the insurer would not reject their insurance claim. It is unfortunate that the Plaintiffs’ interest was not their priority, and they did not sense the urgency to abate the nuisance that the Plaintiffs suffered continuously. This explained the inaction throughout the years. In the meeting of the 1^st Defendant’s management committee on 11^th May 2022[135], Madame Chan rightly and conscientiously pointed out that due to the delay and inaction, the condition of Flat 25D would exacerbate and the Plaintiffs’ loss would keep increasing.

197.  The 1^st and 2^nd Defendants should have taken all necessary steps to collect and/or gather evidence on an urgent basis, and an expert should have been engaged to carry out all necessary tests and to take records and photos of all necessary evidence promptly. The 1^st and 2^nd Defendants must bear in mind the duties to abate nuisance at common law (as well as the duties to properly manage the common areas of Provident Centre under the DMC and the BMO). Gathering evidence against the 4^th Defendant and appeasing an aggressive insurer who might wish to shift the blame to the 4^th Defendant were not reasonable excuses to ignore the duties under the common law, the DMC and the BMO.

198.  The 1^st and 2^nd Defendants’ expert, Dr Lam, did not inspect the Roof and Flat 25D until 17^th January 2022. The delay was inordinate and unacceptable. In my view, had the 1^st and/or 2^nd Defendants acted reasonably, an expert would have been engaged much earlier, and such expert should have, within 4 weeks, completed a report that contained all the necessary data, photo and evidence in relation to the condition of the Roof as well as Flat 25D. What is most ironic is that when Mr Lam attended the Roof and Flat 25D on 17^th January 2022, he merely conducted a “visual inspection” and a “tapping test”. It is hard to see what evidence was preserved and gathered and how the inaction throughout the years had availed the 1^st and 2^nd Defendants (as well as their insurer).

199.  For the above reasons, I conclude that the 1^st and 2^nd Defendants failed to take reasonable steps to abate or nullify the nuisance in respect of the water seepage in Flat 25D within a reasonable time after having constructive knowledge.

200.  In particular, I find that:-

(1) As soon as the 1^st and 2^nd Defendants confirmed that there was water seepage in Flat 25D on 8^th June 2018, they should have immediately taken reasonable steps to ascertain whether the water leakage originated from the areas in the Roof that were not repaired pursuant to the 2016 Engagement Letter. Had reasonable steps been taken and reasonable diligence been exercised, the 1^st and 2^nd Defendants would have known that the water seepage came from the walls of the Water Tank Houses, and they should have immediately taken steps to nullify the water leakage.

(2) The reasonable steps that should have been taken included engaging an independent surveyor (such as Global Generation) to provide advice on the plausible source of the water leakage and the remedial works to be carried out.

(3) It was unreasonable for the 1^st and 2^nd Defendants to assume that the water leakage was caused by the defects in the floor and L-shape junctures (腳線) on the Roof and/or the 4^th Defendant’s negligence and/or defective works.

(4) It was unreasonable for the 1^st and 2^nd Defendants to ignore and/or not to take follow up actions on (i) Mr Lau’s first report dated 23^rd October 2020; (ii) Mr Chiu’s oral advice on 17^th January 2020; and (iii) the 4^th Defendant’s letter dated 26^th June 2020.

(5) The 1^st and 2^nd Defendants did not take any reasonable steps until they engaged Global Generation (which took place sometime after mid-2022). The delay was inordinate and inexcusable.

(6) Had the 1^st and 2^nd Defendants acted reasonably and promptly after 8^th June 2018, they should have identified the source of the water leakage and engaged a contractor, and all necessary works to repair the walls of the Water Tank Houses should have been completed within 12 months. Insofar as the time required is concerned, I take into account the works that were carried out by the contractors throughout the years[136]. I also take into account that whilst it would be necessary to conduct a tender, the 1^st Defendant could rely on the 2^nd Defendant (who employed qualified engineers) and the professional service of an independent surveyor.

201.  In the premises, the 1^st and 2^nd Defendants are liable to the Plaintiffs for nuisance.

Breach of the Provisions of the DMC and the BMO

202.  Whilst section 18 of the BMO requires the 1^st Defendant to maintain the common parts of Provident Centre in good condition and to do all things reasonably necessary to enforce the DMC, clauses 5, 10(a)(7) and clauses 3 and 4(a) under the second schedule of the DMC require the 2^nd Defendant to repair the common areas of Provident Centre and to keep the same in good condition.

203.  For the reasons explained in paragraphs 172 to 201 above, I find that the 1^st and 2^nd Defendants failed to take reasonable steps within a reasonable time to confirm the cause of the water seepage and to carry out works to repair the waterproofing membrane in the walls of the Water Tank House (which are common parts of Provident Centre).

204.  In the premises, I further find that the 1^st and 2^nd Defendants breached their duties under section 18 of the BMO and/or clauses 5, 10(a)(7) and clauses 3 and 4(a) under the second schedule of the DMC. Accordingly, they are also liable to the Plaintiffs on these bases.

E4. The Plaintiffs’ Claims against the 4^th Defendant

205.  For the reasons elaborated in Section E2 above, the source of the water leakage in Flat 25D was the walls of the Water Tank Houses. This had nothing to do with the 4^th Defendant. Thus, the Plaintiffs’ claims against the 4^th Defendant should be dismissed.

206.  In my view, the Plaintiffs’ claims against the 4^th Defendant should also be dismissed on the following grounds.

207.  First, for the reasons explained in paragraphs 96 to 111 above, I reject the suggestion that the 4^th Defendant’s waterproofing works were defective.

208.  Second, the Plaintiffs have failed to plead that the 4^th Defendant owed them a duty of care and none of the facts averred in their statement of claim support the legal conclusion that a duty of care existed.

209.  Third, on the facts and evidence, I am not of the view the 4^th Defendant owed any duty of care to the Plaintiffs in regard to the works that were carried out pursuant to the 2016 Engagement Letter:-

(1) The 4^th Defendant carried out the works in relation to the waterproofing works in respect of the floor and L-shape junctures (腳線) on the Roof simply because he was engaged by the 1^st and 2^nd Defendants under the 2016 Engagement Letter. The duties were owed to the 1^st and 2^nd Defendants, and the 4^th Defendant was not privy to the contractual arrangement between the 4^th Defendant and the 1^st and 2^nd Defendants.

(2) Mr Li (for the Plaintiffs) seeks to rely on the fact that the 4^th Defendant was involved in other works relating to the renovation project in Provident Centre. This is completely irrelevant.

(3) Mr Li also seeks to rely on the fact that back in 2013 or 2014, there was an occasion where the 4^th Defendant’s workers injected materials into the ceiling of Flat 25D with a view to stopping ingress of water tentatively. It is not in dispute that the 4^th Defendants’ workers carried out such work as per the 1^st and 2^nd Defendants’ request. I accept that the 4^th Defendant might owe duties of care to the Plaintiffs in respect of this specific work (which was carried out within Flat 25D). However, I cannot see how the works in 2013 or 2014 might give rise to a duty of care in respect of the works that the 4^th Defendant subsequently carried out pursuant to the 2016 Engagement Letter.

(4) Further, I am not of the view that the authorities cited in Mr Li’s written closing submissions would avail the Plaintiffs. These authorities are concerned with a scenario where contractors negligently caused physical injuries or property damage to third parties. This is not the scenario of the present case.

E5. The 1^st and 2^nd Defendants’ Notice of Contribution/Indemnity against the 4^th Defendant

210.  For reasons set out in Sections E2 and E3, I conclude that the source of the water leakage in Flat 25D was the walls of the Water Tank Houses (which had nothing to do with the 4^th Defendant’s duties under the 2016 Engagement Letter). I also reject the assertion that the works carried out by the 4^th Defendant pursuant to the 2016 Engagement Letter were defective and/or sub-standard.

211.  It follows that the 1^st and 2^nd Defendant’s claims against the 4^th Defendant for indemnity and/or contribution must be dismissed.

E6. The Question of Mitigation

212.  Mr Wong (for the 1^st and 2^nd Defendants) extensively cross-examined the 1^st Plaintiff, and he attacked and criticized the Plaintiffs along the line that they unreasonably failed to repair Flat 25D in a timely manner.

213.  These criticisms are unmeritorious and unjustifiable.

214.  The 1^st Plaintiff was an honest and impressive witness, whose answers were direct and reasonable. He was willing to make concessions in the most sensible manner, and he refused to comment on matters that were beyond his direct knowledge. I have no hesitation to accept the 1^st Plaintiff’s evidence that he and his wife (ie the 2^nd Plaintiff) were retirees, and they relied on the rental income arising from Flat 25D, their savings as well as some modest monthly pension payments to support their living[137].

215.  Based on the objective circumstances, I have every reason to believe that instead of playing games and causing difficulty, the Plaintiffs were eager to rent out Flat 25D as soon as it was possible to do so. This was because the rental income was (and still is) important to them.

216.  The Plaintiffs were able to rent Flat 25D to Mr Hung, despite the water seepage. However, due to the unsatisfactory condition and interference caused by the water seepage, the Plaintiffs were forced to reduce the monthly rental (i) from HK$28,000 to HK$18,800 during period from June 2016 to June 2018; and (ii) from HK$32,000 to HK$25,200 during the period after June 2018. The Plaintiffs also allowed Mr Poon to have the flexibility to terminate the tenancy by giving one-month notice: see paragraph 80(3) above.

217.  In Section E1 (see paragraph 80(6)), I find that Flat 25D was no longer habitable as of June 2020. As evidenced by the photos, the sizeable concrete pieces falling from the ceiling could cause serious physical injury to the tenant and his/her visitors. When the 1^st Plaintiff gave oral evidence, he further mentioned it did not come across his mind that the water seepage might cause leakage of electricity. However, upon reading the minutes of the 1^st Defendant’s meetings, he appreciated the danger. With the benefit of hindsight, the 1^st Plaintiff believed that his decision not to rent out Flat 25D was perfectly correct.

218.  I accept the 1^st Plaintiff’s evidence and suggestion. As evidenced by the minutes of the meetings of the 1^st Defendant’s management committee on 20^th October 2021[138] and 1^st December 2021[139], there was serious water seepage in Flat 25C (which was adjacent to Flat 25D). Ms Hon, who was a manager of the 2^nd Defendant, expressed concern about the personal safety of the owners/residents of Flat 25C (ie Mr Lau and Mrs Lau) and it was proposed that tentative arrangements be made to supply electricity to Flat 25C. Mr Poon also proposed that Mr Lau and Mrs Lau should move out from Flat 25C.

219.  In my view, the Plaintiffs have been reasonable not to lease out Flat 25D to any tenant from June 2020 onwards. This is what a prudent person would have done in the circumstances. In light of the seriousness of the water leakage, I agree that the condition of Flat 25D was hazardous, and there was a real risk that the tenant would suffer serious physical injury when the concrete on the ceiling collapses or when there is electricity leakage if water enters the electricity cables or switches.

220.  The 1^st Plaintiff also pointed out that it would not be economical to keep repairing Flat 25D when the water seepage was recurring. In this connection, in October 2020, the Plaintiffs engaged Sun Ying Loi Construction Co to carry out reparation and renovation works in Flat 25D[140]. However, as the water seepage recurred, Flat 25D was soon damaged again and part of the said reparation works was ruined. At the meeting of the 1^st Defendant’s management committee on 1^st December 2021[141], Mr Chan of Willis also pointed out that there was no point to carry out reparation works before the source of the water leakage was confirmed and the waterproofing works on the Roof were completed.

221.  In the premises, I accept Mr Li’s submissions that until and unless the water leakage problem was cured permanently, any further renovation work to be performed would be futile: see 顏小明 對 多福大厦業主立案法團 (LDBM 79/2007, 12^th August 2012) at paras 44 to 45 (per Deputy District Judge Kot, as Her Honour Judge Kot then was).

222.  However, Mr Wong contends that the Plaintiffs should have applied the specialized waterproofing materials with crystallization ability recommended by Dr Lam[142] to stop the ingress of water in the ceiling of Flat 25D. According to Dr Lam, such materials would have chemical reaction with the concrete in the slaps. The gross effect is that some reformed substance will be created in the slap, and the same is capable of blocking water seepage for at least 5 years. Dr Lam even said that the materials that he recommended had been sold in the market since1980s and widely used in huge projects worldwide.

223.  I have no hesitation to reject Dr Lam’s opinion:

(1) Dr Lam’s assertions are not supported by scientific analysis and objective data. As pointed out by Mr Li, Dr Lam does not refer to any academic articles in his experts’ reports. Had Dr Lam’s assertions been supported by some academic authorities with meaningful scientific analysis and objective data, he would have cited the same and elaborated thereon in his experts’ reports.

(2) If there were some materials with crystallization abilities that are capable of blocking water seepage for more than five years without adverse consequences, water leakage would be a rarity, and all properties owners can keep applying such materials to block ingress of water. There will be no more water seepage, and a vexing problem that has caused a plethora of disputes can be resolved.

(3) This is too good to be true.

(4) When Mr Poon testified, he said he found it surprising that a material that was so magnificent existed, and this went beyond his imagination. Along the same vein, the 1^st Plaintiff said that Dr Lam’s opinion shocked him. Whilst the 1^st Plaintiff had no expertise in building materials and chemistry, his experience was such that injection of materials into ceilings could not stop water seepage. As mentioned, back in 2013 or 2014, the 4^th Defendant’s workers were arranged to inject materials into the ceiling of Flat 25D. However, the water seepage recurred very soon, and the water seepage was digressed to areas that were not affected previously.

(5) The 1^st Plaintiff’s evidence is consistent with the opinion expressed by Ms Lau. She opines that the method proposed by Dr Lam is not advisable. From her experience, it would not be effective to inject materials into ceilings. This method often causes more harm than good as the water will simply find it ways to other areas, thereby creating new problems and causing further physical damage. Ms Lau’s opinion is consistent with and supported by Deputy District Judge Simon Ho’s observation that “water is notoriously able to find conduits to run along and to penetrate weak points …”: Yik Yuen Ling v Tso Wing Yan (supra) at para 122. I accept and prefer Ms Lau’s opinion.

(6) Out of desperation, Mr Wong criticizes Ms Lau for not having heard of the materials recommended by Dr Lam and not seeking to familiarize herself with these materials. In making these criticisms, Wong makes a false assumption that Dr Lam’s opinion is sound and that there are in fact some perfect materials that are capable of blocking water seepage for at least 5 years without creating any side effect.

(7) In my view, the truth is that the materials in question simply do not carry the magical effects alleged by Dr Lam, and thus they are neither well known nor popular. This is the reason why Ms Lau and Mr Hau (who are experienced experts) as well as Mr Chiu (who is an experienced frontline technician and an honest witness) have never heard of them.

224.  In the premises, it was reasonable for the Plaintiffs to reject the proposal form Dr Eddie Lam.

225.  After all, Dr Lam is an expert engaged by their opponents. It was understandable why the Plaintiffs were skeptical about his assertions. After hearing Dr Lam’s evidence and Mr Wong’s submissions, I am convinced that the Plaintiffs’ skepticism was wholly justified. Any reasonable person would have taken the stance that the Plaintiffs took.

226.  Mr Wong also criticizes the Plaintiffs for having no intention to repair Flat 25D in a timely manner, and this caused the condition of Flat 25D to deteriorate. As pointed out in paragraph 53(2) above, in his oral opening submissions, Mr Wong contends that the Plaintiffs should have immediately carried out reparation works after 30^th April 2024[143] when their solicitors were informed that part of the works recommended by Global Generation (including the works relating to the walls of the Water Tank Houses) were completed. In his written submissions, Mr Wong further submits that it was unreasonable for the Plaintiffs to wait until Yan Cheong completed all the works recommended by Global Generation. Mr Wong emphasizes that there has been no complaint of water seepage after October or November 2023.

227.  Mr Wong’s submissions are unreal and unmeritorious, and I reject the same:-

(1) Any reasonable person in the circumstances would have awaited Yan Chong to complete all the works recommended by Global Generation as it was obvious that their recommendations were to address the water leakage problem in Flat 25D. This was exactly why the 1^st and 2^nd Defendants offered an undertaking to implement all these recommendations and the Plaintiffs accepted the same.

(2) I cannot see how Mr Wong could seriously suggest that the Plaintiffs should have felt assured and started repairing Flat 25D when only part of the 1^st and 2^nd Defendants’ undertaking was fulfilled. If Mr Wong were correct, the works under the remaining part of the undertaking that had not yet been fulfilled as of 30^th April 2024 would be completely pointless and ignorable under the agreement or consensus between the parties. If this were the case, why would the 1^st and 2^nd Defendants’ undertakings cover these works? Mr Wong has no answer. In my view, the Plaintiffs were entitled to wait until the 1^st and 2^nd Defendants fulfilled the entirety of the undertaking. These were what the 1^st and 2^nd Defendants offered and what the Plaintiffs accepted.

(3) Further, Mr Wong’s submissions are based on the assumption that as of 30^th April 2024, it was already known to all the parties that the walls of the Water Tank House were the only source of water leakage and that only Ms Lau’s opinion in this regard was correct. However, the reality was that as of 30^th April 2024, the parties were hotly contesting the present proceedings, and the experts engaged by the parties advanced conflicting theories as to the cause of the water seepage. Bearing in mind the conflicting opinions expressed by the experts and the conflicting arguments advanced by the 1^st, 2^nd and 4^th Defendants, it was reasonable for the Plaintiffs not to commence reparation works when the 1^st and 2^nd Defendants expressly admitted that the waterproofing works in respect of various parts of the upper roof (such as the surface or top of the Water Tank Houses) had not yet been completed[144]. In my view, as of 30^th April 2024, the Plaintiffs were reasonable to take the view they could not rule out the possibility that the water seepage might come from the areas in respect of which reparation works had not yet been completed. The Plaintiffs cannot be criticized for being prudent and cautious.

(4) Moreover, the solicitors’ correspondence reveals that the Plaintiffs struggled to obtain information from the 1^st and 2^nd Defendants with regard to the progress of the reparation works recommended by Global Generation, and only some general information was provided to the Plaintiffs. In the circumstance, the Plaintiffs and their professional advisors were not in a position to assess the correlation between different parts of the works recommended by Global Generation.

(5) In light of the circumstances set out above, as of 30^th April 2024, it was plainly impossible to conclude that the water seepage problem had already been cured on a permanent basis.

228.  For the above reasons, I reject the 1^st and 2^nd Defendants’ unfounded allegations that the Plaintiffs failed to mitigate their loss. I find that the Plaintiffs acted reasonably at all material times.

E7. Quantum

Rental Income

229.  In Section E3 (see paragraph 200), I find, inter alios, that (i) the 1^st and 2^nd Defendants should have promptly taken steps to identify the source of water seepage and to nullify the nuisance after 8^th June 2018; and (ii) had reasonable steps been taken with due diligence, all the reparation works that cure the water seepage would have been completed within around 12 months. This would have been around June 2019 (say 1^st June 2019)[145].

230.  The 1^st and 2^nd Defendants should be liable for the Plaintiffs’ loss of rental income from 1^st June 2019 onwards until the time when the Plaintiffs are able to rent out Flat 25D again. This will only happen after the contractor engaged by the Plaintiffs repairs Flat 25D.

231.  As mentioned, only on 3^rd October 2024 (ie less than 2 weeks before the present trial commenced) did the 1^st and 2^nd Defendants, through solicitors, inform the Plaintiffs that all the reparation works recommended by the Global Generation had been completed[146]. However, as of June 2024, the Plaintiffs had already engaged a professional surveyors’ firm, namely TLS & Associates Ltd (“TLS”)[147], to conduct a tender, and quotations from five contractors were received.

232.  Since the Plaintiffs were fully occupied by the present trial[148], it would be reasonable for them to resume the liaison with TLS after the present trial completed on 29^th October 2024. TLS received the quotations more than four months ago on 17^th June 2024[149]. As such, it would be necessary for TLS to obtain updated quotations from the contractors. Further, it may take time for TLS to sort out and confirm the terms of the engagement and the relevant arrangement with the contractor to be chosen by the Plaintiffs. According to the 1^st Plaintiff, he estimated that it would take two months for the contractor to complete the reparation works in Flat 25D. This estimation is fair and not seriously challenged.

233.  Taking into account the matters canvassed above as well as the fact that it will take some time to locate a tenant, I am of the view that the Plaintiffs will not be able to rent out Flat 25D until February 2025 (say 1^st February 2025). This is about 3 months from the day (ie 29^th October 2024) when it would be reasonable for the Plaintiffs to resume liaising with TLS.

234.  In the premises, I find that the 1^st and 2^nd Defendants should be liable for the Plaintiffs’ loss of rental income from 1^st June 2019 to 1^st February 2025.

235.  It is the Plaintiffs’ pleaded case that they suffer loss of rental income at the rate of HK$38,000 per month[150]. However, when the 1^st Plaintiff testified, he fairly and frankly accepted that the rate of HK$38,000 per month is based on his estimate that Flat 25D be rented out on the basis that it is fully furnished.

236.  In this connection, I accept Mr Wong’s submissions that as the Plaintiffs’ claims are tortious in nature, he may only seek damages on the basis that he be put in a position that he would have been in had the wrong not been committed: see Ng Chi Kwan Danny Summer v Yeung Yiu Kwan [2014] 5 HKLRD 744 at paras 125-126 (per DHCJ Marlene Ng, as Marlene Ng J then was).

237.  However, I am unable to accept Mr Wong’s contention that the Plaintiffs cannot prove he would have been able to rent out Flat 25D after June 2020. As I understand, the crux of Mr. Wong’s argument is that the Plaintiffs could not have known what would have happened had there been no water seepage. This argument is simply contrived. There is not a shred of evidence showing that but for the 1^st and 2^nd Defendants’ flagrant and continuous breach of duties, Mr. Hung and his family would have wished to leave Flat 25D or the Plaintiffs would have faced difficulty to rent out Flat 25D.

238.  On the evidence before the Court, I am satisfied that had the 1^st and/or 2^nd Defendants promptly abated the nuisance in discharge of their duties, Mr Hung would have continued the tenancy relationship with the Plaintiffs. I fully accept the 1^st Plaintiff’s evidence that he and the Hungs had a very harmonious and friendly relationship all along, and they tried to accommodate each other. Having heard the 1^st Plaintiff’s evidence, I am of the view that he is a reasonable person who truly understands where others come from, and there is no surprise that he had a very good relationship with his tenant and his family. The 1^st Plaintiff informed me that he was very grateful to Mr Hung and Mrs Hung who were willing to tolerate the unsatisfactory condition of Flat 25D for more than 6 years, and he felt sorry that the water seepage problem was not resolved. The 1^st Plaintiff also told me that Mr Hung and Mrs Hung’s son (who grew up in Flat 25D since he was born) did not wish to leave the property, and he felt upset about the situation. Eventually, a photo was taken before the Hungs left. I have no reason to doubt the 1^st Plaintiff’s evidence.

239.  I also fully accept the 1^st Plaintiff’s evidence that before Mr Hung and Mrs Hung left Flat 25D, he had a conversation with Mrs Hung, and Mrs Hung indicated that but for the water seepage problem, she and her husband would have been willing to rent Flat 25D at the monthly rental of HK$34,000 after the term of the pre-existing tenancy agreement dated 12^th June 2018 came to an end.

240.  In the premises, I find that but for the 1^st and 2^nd Defendants’ breach of duties and/or tortious conduct, the Plaintiffs would have continuously rented Flat 25D to Mr Hung at the monthly rental of HK$34,000 after the pre-existing tenancy ended on 11^th June 2020[151].

241.  Accordingly, the Plaintiffs are entitled to damages in respect of loss of rental income as follows:-

Period	Amounts
Loss of rental income from 1st June 2019 to 11th June 2020 (HK$6,800[152] x 12 months[153] + HK$6,800 x 11/30[154])	HK$84,093.33
Loss of rental income from 12th June 2020 to 1st February 2025[155] (HK$34,000 x 56 months[156] + HK$34,000 x 16/31[157])	HK$1,921,548.38
	Total: HK$2,005,641.71

242.  In his closing submissions, Mr Wong belatedly submitted that government rent and rates as well as well as management fees should be deducted from the award in favour of the Plaintiffs. This point was not raised in the pleadings or during opening submissions. It was not even put to the 1^st Plaintiff when he was cross-examined. In the circumstances, the Plaintiffs have been deprived of the opportunity to address the point. It is unfair to ambush the Plaintiffs in the late state of the proceedings in this manner. In any event, as the 1^st and 2^nd Defendants are the parties who seek to allege that government rent and rates and management fees should be deducted, they carry the burden to prove that the Plaintiffs and Mr Hung would have agreed that the Plaintiffs should bear the government rent and rates as well as management fees. The 1^st and 2^nd Defendants also bear the burden to prove the quantum in question. Without cross-examining the 1^st Plaintiffs on these matters, the 1^st and 2^nd Defendants are unable to adduce a shred of evidence.

Re-instating Damaged Renovation Works that were already Carried Out

243.  It is not in dispute that part of the renovation works carried out by Sun Ying Loi Construction Co were damaged, and the experts agree that the expenses for reinstating these works be assessed at HK$4,683.33[158].

Reparation Works to be carried-out

244.  In 2022, the parties’ experts inspected Flat 25D for the purpose of assessing damage. However, due to continuous water leakage, the condition of Flat 25D has significantly deteriorated since 2022.

245.  As mentioned, on 17^th June 2024, TLS received five quotations from contractors for carrying out reparation works in Flat 25D. Whilst the highest quote was HK$691,094, the cheapest quote was HK$366,240. On this basis, the Plaintiffs claim damages of HK$366,240, being expenses for reinstating and repairing Flat 25D.

246.  I accept the 1^st Plaintiff’s evidence that in around early November 2023, a Mr Lo of Yan Cheong gave an express warning that the Plaintiffs must exercise caution when the ceiling in Flat 25D is repaired in the future. Given the seriousness of the damage in Flat 25D, if the reparation works were not carried out cautiously, the waterproofing membrane that Yan Cheong constructed on the Roof would be damaged. The consequence is that the 10-year warranty provided by Yan Cheong would cease to apply, and the Plaintiffs may need to bear the expenses for carrying out reparation works and compensate other individual owners if there is water leakage.

247.  It was in these circumstances that the Plaintiffs engaged TSL, which is a professional surveyors’ firm, to invite quotations from qualified and reputable contractors. In my view, what the Plaintiffs seek to do is wholly reasonable and unnecessary.

248.  However, Mr Wong criticizes the Plaintiffs for not adducing expert evidence to prove that it is necessary to incur HK$366,240 to reinstate or repair Flat 25D. I reject Mr Wong’s contention, which is, again, pedantic. The quotations are the best evidence[159]. There is no suggestion that the quotations are bogus or inflated. The evidence shows that five bona fide contractors nominated by a professional surveyors’ firm seek to compete for a job. It is plain that the cheapest quote of HK$366,240 is a reasonable market price. It is most reasonable for the Plaintiffs to choose the contractor that charges the cheapest price. In my view, the criticism against the Plaintiffs is ill founded and should not have been made.

249.  In the premises, I award damages in the sum of HK$366,240 in respect of the expenses for reinstating and repairing Flat 25D.

Expenses on Ms Lau’s 1^st Report dated 23^rd October 2020

250.  I disagree with Mr Wong’s suggestion that the fees in respect of Ms Lau’s report dated 23^rd October 2020 should form part of the costs of the action.

251.  In Chau Wai Hung & Anor v. Lam Tak Chuen (supra) at para 89(1), DHCJ Phoebe Man allowed the plaintiff’s claim for the fee in respect of a pre-action report (as damages) on the basis that the report was prepared to investigate the cause of the water seepage in order to limit damage

252.  Like the scenario in Chau Wai Hung, the Plaintiffs engaged Ms Lau to prepare the report dated 23^rd October 2020 in order to identify the cause(s) of the water leakage and to convince the 1^st and 2^nd Defendants to take timely action, such that their damage could be limited.

253.  I am of the view that the fee charged by Ms Lau, ie HK$50,000, is reasonable. I allow this sum in full.

General Damages: Inconvenience, Annoyance and Discomfort

254.  Mr Li asks me to award general damages in the sum of HK$50,000.

255.  He refers me to Yeung Yik Chun v Wong Lai Ming & Anor [2023] HKDC 1160 at paras 166-167. In that case, the plaintiff did not live in the subject property. However, he returned to the property from time to time to attend to the water dripping, clean up the molds and monitor the development. The subject property had been affected by water seepage for about 5 years. Deputy District Judge Michelle Lam (as Her Honour Judge Michelle Lam then was) awarded the plaintiff general damages of HK$30,000 for the inconvenience and discomfort that he suffered.

256.  Mr Wong refers me to Wen Shek Tun & Anor v. Chan Wai Fong & Anor [2022] HKDC 856 at para 22. There, Master Maurice Lam awarded general damages of HK$20,000 to a plaintiff who did not live in the subject property. In that case, the water seepage had last for about 4.5 years.

257.  Whilst each case will have to be decided on its own facts, I have considered the two cases cited by counsel as well as the cases referred to in Yeung Yik Chung v Wong Lai Ming (supra) at para 166.

258.  I am of the view that in the circumstances of the present case, an award of HK$30,000 will be sufficient to compensate the Plaintiffs for the inconvenience, annoyance and discomfort that they have been suffering since June 2019.

Fees of Estate Agent

259.  As explained, the Plaintiffs should be compensated on the basis that he be put in a position that he would have been in had there been no wrong and/or breach of duties on the part of the 1^st and 2^nd Defendants. As such, they are not entitled to claim the expenses to be incurred for engaging estate agents.

Sum Up

260.  To sum up, the Plaintiffs are entitled to damages as follows:-

Loss of Rental Income	HK$2,005,641.71
Damaged Renovation Works that were already Carried Out	HK$4,683.33
Reparation Works to be carried-out	HK$366,240
Ms Lau’s Report dated 23rd October 2020	HK$50,000
General Damages	HK$30,000
Total:	HK$2,456,565.04

F. Order and Disposition

F1. The Substantive Claims and Interest

261.  I order the 1^st and 2^nd Defendants to pay damages of HK$2,456,565.04 to the Plaintiffs.

262.  The Plaintiffs are entitled to interest at half judgment rate on the sums of HK$2,005,641.71, HK$50,000 and HK$30,000 from 1^st June 2019 to the date of this judgment, and thereafter interest at judgment rate until payment in full.

263.  I dismiss the Plaintiffs’ claims against the 4^th Defendant in the original action.

264.  I dismiss the 1^st and 2^nd Defendants’ claims against 4^th Defendants under the amended notice of contribution and/or indemnity dated 4^th November 2022.

F2. Costs

265.  Costs should follow the event.

266.  I see no reason why the 1^st and 2^nd Defendants should not pay the Plaintiffs’ costs in this action.

267.  As regards the costs of the 4^th Defendant, my tentative view is as follows:-

(1) Both the Plaintiffs and the 1^st and 2^nd Defendants are the unsuccessful parties viz-a-viz the 4^th Defendant.

(2) The main issues in original action and the amended contribution notice (ie whether the floor and L-shape junctures (腳線) on the Roof were a source of the water leakage and whether the 4^th Defendants’ works were defective) substantially overlap. The issues that do not overlap (such as whether the 4^th Defendant owed a duty of care to the Plaintiffs) did not take up much time at the trial.

(3) With a view to saving judicial resources, time and taxation expenses, instead of ordering 2 sets of costs in favour of the 4^th Defendant, it would be desirable to order one set of costs that is apportioned. This is because it would be extremely difficult, if not practically impossible, to distinguish the 4^th Defendant’s costs in the original action from the 4^th Defendant’s costs in the amended contribution notice. This exercise will be artificial, and the taxation process will be a nightmare.

(4) Bearing in mind the following matters, it would be just and fair to order (i) the 1^st and 2^nd Defendants to pay 85% of the 4^th Defendants’ costs in this action; and (ii) the Plaintiffs to pay 15% of the 4^th Defendants’ costs in this action.

(5) First, I am unimpressed by the 1^st and 2^nd Defendants’ litigation conduct, which lengthened the trial, complicated the dispute and unnecessarily escalated the costs incurred by the 4^th Defendant. In this connection, the following matters are some non-exhaustive examples:

(a) The 1^st and 2^nd Defendants’ contention that the Plaintiffs failed to mitigate loss is wholly unmeritorious and unjustified. Considerable time was spent on pursuing this contention at trial.

(b) As evidenced by the contents of this judgment (which I do not intend to repeat), the 1^st and 2^nd Defendants pursued a vast array of highly artificial yet unmeritorious contentions. Regrettably, some of these contentions even lack intellectual honesty. For instance, the contention that there was no water seepage after 2022 (or it cannot be shown that there was water seepage after 2022) flies in the face of the overwhelming incontrovertible evidence before the Court[160]. The barrel-scrapping approach adopted by the 1^st and 2^nd Defendants is the antithesis of effective resolution of disputes.

(c) Throughout the trial, there were numerous occasions where 1^st and 2^nd Defendants adamantly pursued ill-founded technical objections that caused unnecessary disruption. A salient example was the attempt to stop Mr. Li from conducting cross-examination in relation to the walls of the Water Tank Houses on the alleged ground that the Water Tank Houses were not within the definition of the Roof as pleaded (which was plainly an incorrect assertion)[161]. This kind of groundless objections should not have been made at all.

(d) Whilst the 1^st and 2^nd Defendants’ disclosure was inadequate, those who were familiar with the records and documents have been hiding behind the scenes. For instance, the 1^st and 2^nd Defendants produced an unsigned chronology[162], which is said to be the records of the relevant events and which seems to form the basis of the pleas in the 1^st and 2^nd Defendants’ amended defence. However, this important document is not signed at all, and it is impossible to find out the person(s) who created this document. What is also surprising is that Mr Leung and Madame Chan who were arranged to make affirmations in response to the Plaintiffs’ specific discovery application and interrogatories knew very little about the records and documents of the 2^nd Defendant, and they could not meaningfully confirm whether the documents sought existed or not. In the circumstances, in the trial considerable time was spent to ascertain factual matters, but the witnesses from the 1^st and 2^nd Defendants could offer minimal assistance. This is not satisfactory.

(e) The 1^st and 2^nd Defendants’ expert evidence is also unhelpful. More questions than answers were raised, and no objective data and scientific analysis were provided.

(6) Second, I take into account the question of blameworthiness. It is true that like the 1^st and 2^nd Defendants, the Plaintiffs brought an unsuccessful claim against the 4^th Defendant. However, the 1^st and 2^nd Defendants were the ones who put the Plaintiffs in a difficult and unenviable position, and they flagrantly and unreasonably ignored their duties, knowing that the Plaintiffs would suffer. Had the 1^st and 2^nd Defendants acted reasonably, the water seepage would have stopped much earlier, and this action would not have arisen at all.

(7) Third, I take into account that some issues (such as whether the 4^th Defendant owed a duty of care to the Plaintiffs) have nothing to do with the 1^st and 2^nd Defendants. However, these issues were straightforward, and did not consume much time and resources.

268.  In the premises, I make a costs order nisi that:-

(1) The 1^st and 2^nd Defendants do pay the Plaintiffs’ costs in this action, including all costs previously reserved, to be taxed if not agreed (with certificate for counsel);

(2) The 1^st and 2^nd Defendants do pay 85% of the 4^th Defendant’s costs in this action, including all costs previously reserved, to be taxed if not agreed (with certificate for counsel); and

(3) The Plaintiffs do pay 15% of the 1^st and 2^nd Defendants’ costs in this action, including all costs previously reserved, to be taxed if not agreed (with certificate for counsel).

269.  I thank counsel for their assistance.