KWOK KIN NAM AND ANOTHER v. IP SAU CHUN SUSANNA AND ANOTHER

DCCJ 3185/2021

[2026] HKDC 912

IN THE DISTRICT COURT OF THE

HONG KONG SPECIAL ADMINISTRATIVE REGION

CIVIL ACTION NO 3185 OF 2021

------------------------------

------------------------------

------------------------------

JUDGMENT

------------------------------

A.  INTRODUCTION

1.  This is a water seepage case. The Plaintiffs (“Ps”) are the registered owners of Flat 4D (“4D”) of Kiu Wang Mansion in Ho Man Tin (“Mansion”) and the Defendants (“Ds”) are the registered owners of the Flat 5D (“5D”) of the Mansion.

2.  Ps’ case is that the water seepage started in 2017 and affected the master bedroom (“4D Master Room”), the master bathroom (“4D Master Bath”) and guest bedroom (“4D Guest Room”) of 4D (collectively referred to as the “Affected Rooms”). Ds deny that 5D was the source of the seepage.

3.  At trial, Ps were represented by Ms Eugena Yang and Ds by Mr Brian Fan.

4.  Before the trial began, Ms Yang confirmed that Ps would no longer pursue their claim for alternative accommodation. In those circumstances, the attendance of three of Ds’ witnesses was dispensed with.

5.  By the Order dated 8 September 2022 of Master Jocelyn Leung (“Expert Directions”), leave was granted to adduce expert evidence on liability and quantum from Mr Leung Ka-chun (“Mr Leung”) for Ps and Ms Lau Shan-la (“Ms Lau”) for Ds (collectively referred to as the “Experts”).

6.  The main dispute at the trial is whether the seepage was caused by the defects in the waterproofing membrane beneath the shower tray in the guest bathroom of 5D (“5D Guest Bath”). The parties accepted that the outcome of the case would largely turn on the expert evidence.    

B.  PRELIMINARY ISSUE

7.  Pursuant to the Expert Directions, the parties filed the Joint Expert Report dated 13 February 2023 (“Joint Report”).

8.  In addition to the Joint Report, Ps unilaterally filed the following documents:-

(a)  Mr Leung’s report dated 22 July 2022[1];

(b)  Mr Leung’s report dated 21 March 2023; and

(c)  Mr Leung’s report dated 19 July 2024 (collectively referred to as the “Additional Reports”).

9.  Mr Fan complained that the Additional Reports had been filed without leave of the Court. Despite Ds’ objection, Ps insisted on including these documents in the trial bundles.

10.  Mr Fan submitted that the Additional Reports were inadmissible for that reason alone; Chau Yuen Heung v JekcoElevators Ltd [2021] HKCFI 1095 at §97; Wong Kit Ming v IO of Wah Hoi Mansion [2019] HKDC 1652 at §§50, 68, 73; Lan Lai Ling v Wong Man Kit [2024] HKDC 459 at §§30, 57, 61.

11.  Mr Fan further pointed out that, in the reports dated 21 March 2023 and dated 19 July 2024, Mr Leung sought to raise new allegations based on further inspections on 4D carried out by Mr Leung alone after the Joint Report without prior notice to Ds. It was Mr Fan’s submissions that it was impermissible for an expert to use a supplemental report to cure deficiencies in earlier reports without any direction or leave from the Court; Wong Kit Ming at §§70-71; Kan Lai Ling at §24.

12.  Ms Yang accepted that no leave was granted to Ps to file the Additional Reports. She nevertheless proposed to keep those documents in the trial bundles “for the Court’s reference”.  

13.  I agreed with Mr Fan’s submissions. In my view, the way Ps handled the Additional Reports leaves much to be desired. There was no application, even at trial, for retrospective leave to adduce them. If the documents were inadmissible, there was no good reason for them to remain in the trial bundles. I therefore ordered that the Additional Reports be removed from the bundles, and that no reference should be made to them at trial.

C.  BACKGROUND

14.  Although 5D is directly above 4D, their internal layouts are not exactly the same. Directly above 4D Guest Room is the master bathroom of 5D (“5D Master Bath”), and directly above 4D Master Bath is 5D Guest Bath. There is no evidence as to which flat’s layout has been altered, and nothing turns on that issue. For ease of reference, I annex a floor plan, helpfully prepared by Mr Fan, which juxtaposes the floor plan of 4D with that of 5D.

15.  There is no dispute that the seepage problem first occurred in 2017 and that a complaint was made to the Joint Office of the Buildings Department & Food and Environmental Hygiene Department (“Joint Office”) in July 2017. After investigation, a Nuisance Notice dated 26 October 2017 (“2017 Nuisance Notice”) was issued to Ds requiring them to repair the drainage pipe connecting to the floor drain outlet of 5D Master Bath[2].

16.  By a letter dated 28 November 2017, the Joint Office informed Ps that repairs to the floor drain outlet of 5D Master Bath had been carried out but seepage at 4D persisted. The letter stated that the Joint Office would consider arranging a “professional investigation”.

17.  Further investigation was then carried by Pioneer Management Ltd. In its report dated 23 March 2018 (“2018 Pioneer Report”), Pioneer recorded, among other things, that:-

(a)  Seepage was “consistently all day long” at the ceiling and wall of the 4D Guest Room, ceiling of the “2^nd Guest Bedroom” (which is referred to as “4D Room One” in the Joint Report and at trial) and the ceiling of 4D Master Bath;

(b)  Moisture content at those locations ranged from 8.9 to 68.9;

(c)  Colour water tests were carried out from the drainage inlets at 5D on 7 August 2017 and 24 October 2017. No colour dye was observed at the affected seepage areas, and leakage of the drainage pipe remained uncertain;

(d)  Pond test was carried out to the shower trays and floor slabs of both 5D Master Bath and 5D Guest Bath, together with spray tests to the enclosing walls of the shower trays, on 2 January 2018. No dye was noted at affected seepage areas on 2 January 2018 and 5 February 2018, and floor slab infiltration was considered unlikely;

(e)  Moisture content was monitored on 25 December 2017, 2 January 2018 and 5 February 2018. No continuous water dripping was noted, and leakage from water supply pipe was considered unlikely;

(f)  Moisture content was not correlated with weather conditions, and rainwater leakage was considered unlikely; and

(g)  The source of water seepage was recorded as “uncertain”.

18.  By a letter dated 12 April 2018, the Joint Office informed Ps that, as Pioneer had been unable to ascertain the source of seepage, the Joint Office would cease following up on Ps’ complaint.

19.  In August 2019, Ps made a further complaint of seepage to the Joint Office. An inspection of 4D on 9 August 2019 confirmed the existence of water seepage in the 4D Master Bath.

20.  On 26 August 2019, the Joint Office carried out coloured water tests from the drainage inlets at 5D. The results did not show that the seepage at 4D was related to the drainage inlets of 5D. The Joint Office therefore instructed P2H Design Associates (“P2H”) to conduct a further professional investigation.

21.  In an inspection report dated 10 November 2019 (“2019 P2H Report”), P2H stated that the source of seepage had been identified as infiltration from the floor slab of 5D Guest Bath. P2H did not conduct any pond test on the said floor slab, but relied on protimeter readings, infrared (“IR”) thermography and microwave tomography obtained at 4D.

22.  As a result of the 2019 P2H Report, a further nuisance notice dated 22 January 2020 (“2020 Nuisance Notice”) was issued to Ds in respect of the floor slab of 5D Guest Bath.

23.  In a further inspection report dated September 2020 (“2020 P2H Report”), P2H stated that the seepage problem persisted and recommended prosecution.

24.  The documentary evidence shows that the following remedial works were carried out after the issuance of the 2020 Nuisance Notice:-

(a)  On 8 May 2020, Beliving Interiors Ltd (“Beliving”) applied four layers of waterproof glue to the floor of 5D Guest Bath;

(b)  On 18 June 2020, Creator Design Limited (“Creator”) applied a further three layers of waterproof coating to the floor of 5D Guest Bath; 

(c)  On 28 July 2020, Creator applied an additional waterproof layer to the floor of 5D Guest Bath; and

(d)  Between 17 and 23 November 2020, Wing Fai Renovation Design Company[3] (“Wing Fai”) removed the tiles and redid the waterproof layer to the entire floor slab of 5D Guest Bath (“2020 Renovations”).

25.  Before the commencement of the 2020 Renovations, Ps engaged Mr Leung to investigate the seepage problem. He inspected 4D on 8 October 2020 and subsequently issued the Seepage Investigation Report dated 9 November 2020 (“2020 Leung Report”) in which he recorded the following test results:-

(a)  The IR scans showed the existence of moisture at 4D Master Bath and 4D Guest Room;

(b)  The electrical conductivity sensing (“ECS”) showed the existence of moisture at 4D Master Bath and 4D Guest Room;

(c)  The chloride and ammonium tests on specimen obtained from the Affected Rooms both yielded positive results;

(d)  A visual inspection of the external wall of the Mansion showed no sign of seepage;

26.  Referring to the 2020 P2H Report and the 2020 Nuisance Notice, Mr Leung concluded in the 2020 Leung Report that the source of seepage at 4D was the “water facilities” of 5D Guest Bath[4]. It is noted that no tests were carried out at 5D by him.

27.  Despite the repairs referred to in paragraph 24 above, seepage continued in the Affected Rooms.

28.  On 8 July 2021, Ps commenced the present proceedings against Ds.

D.  ISSUES IN DISPUTE

29.  According to the Agreed List of Issues, the questions arising in this case are:-

(a)  What is the extent (if any) of water seepage affecting 4D?

(b)  Does the water seepage affecting 4D originate from 5D in the manner pleaded in Ps’ Statement of Claim?

(c)  Subject to the factual findings made, are Ds liable to Ps in negligence, nuisance, breach of Deed of Mutual Covenant and/or breach of Building Management Ordinance, as pleaded in Ps’ Statement of Claim?

(d)  If Ds are liable, what loss have Ps suffered as a result of the relevant breaches?

(e)  Are Ps entitled to the reliefs claimed in their Statement of Claim?

30.  Issues (a) to (c) concern liability. The main issue is whether Ps are able to prove that the 5D Guest Bath was the source of seepage. There is no real dispute that Ds would be liable if 5D Guest Bath were found to be the source. Issues (d) and (e) concern quantum and relief.

E.  APPLICABLE PRINCIPLES

31.  The applicable legal principles are not in dispute and were helpfully set out in Yeung Yik Chun v Wong Lai Ming [2023] HKDC 1160 as follows:-

(a)  There is no presumption that the source of water must come from the unit immediately above the unit affected. The plaintiff bears the burden to prove on a balance of probabilities that the source of the water seepage is from the defendant’s property; Hui Ling Ling v Sky Field Development Ltd, CACV 122/2012, 22 March 2013;

(b)  It is not for the defendant to find out or identify the correct source of the water leakage or to prove that its origin did not come from his property;

(c)  Expert evidence on identifying the source of water seepage is  merely providing assistance to the Court, and such evidence is not binding upon the Court. The Court can and should make its own judgment by considering all the materials available: Grand Wayfair Investment Company Limited v Chan Yung Kan, CACV 238/2013, 26 September 2014 at §§37-44;

(d)  It is legitimate for an expert to reach a conclusion on the source of water seepage without conducting any water tests but by deduction, i.e. by excluding other possible sources of water seepage, provided that there is factual basis from which the conclusion is reached: Leung Yung Chun v Chan Wing Sang [2000] 1 HKLRD 456 at §§460J-461A.

F.  FACTUAL EVIDENCE

32.  There were three factual witnesses at trial, namely the 1^st Plaintiff (“P1”), the 1^st Defendant (“D1”) and Mr He Jiansheng (“Mr He”), the proprietor of Wing Fai.

F1.  The 1^st Plaintiff

33.  P1 and his wife, the 2^nd Plaintiff (“P2”), are the joint owners of 4D. There are three bedrooms in 4D with a total area of about 840 square feet. Before the seepage problem arose in 2017, they lived there with their son, daughter‑in‑law and P1’s elderly mother. P1 and P2 occupied 4D Master Room, their son and daughter‑in‑law occupied 4D Guest Room, and P1’s mother occupied Room One.

34.  On 25 February 2017, P1 discovered water seepage in the 4D Guest Room, with obvious signs on the ceiling and wall accompanied by a foul smell. He immediately contacted the building management. When the manager informed Ds of the seepage, they suggested that it might have been caused by the external wall. P1 then went up to 5D and invited Ds to come down to 4D so that they could jointly identify the source of the seepage. D1 refused, saying the seepage had nothing to do with her and suggesting that P1 seek assistance from the Food and Environmental Hygiene Department (“FEHD”). P1 accepted that suggestion and lodged a seepage complaint with the Joint Office.

35.  On 7 August 2017, staff from the Joint Office attended 4D Guest Room for inspection. On 8 August 2017, the Joint Office confirmed that seepage occurred at the ceiling and wall of 4D Guest Room. After further follow‑up inspections on 21 August and 1 September 2017, the Joint Office concluded that the source of seepage was 5D Master Bath.

36.  On 1 November 2017, the Joint Office issued the 2017 Nuisance Notice to Ds requiring them to carry out proper repairs in 5D. On 28 November 2017, the Joint Office informed P1 that repairs had been done at 5D but seepage was still continuing. When P1 contacted Ds, D2 told him that renovation works at 5D had been completed and refused to come down to inspect 4D. Subsequent calls by P1 to D2’s mobile phone went unanswered.

37.  On 8 December 2017, the Joint Office appointed a government contractor to conduct further investigations. On 12 April 2018, the Joint Office notified Ps that they were unable to ascertain the cause of seepage. However, the seepage continued with serious conditions in 4D Master Room and 4D Master Bath.

38.  As P1’s daughter‑in‑law was pregnant, P1’s mother gave up Room One to his son and daughter‑in‑law and moved to sleep in the living room. Eventually, the family decided to move out and rent another flat.

39.  Around March 2018, Ps noticed that the seepage problem and foul smell had spread from 4D Guest Room to 4D Master Bath. They observed extensive damage said to be caused by the seepage, including paint and concrete spalling from the ceilings and damage to a hanging cabinet.

40.  In July 2018, P1’s mother insisted on returning to live at 4D. Around the same time, P1’s daughter‑in‑law gave birth on 18 July 2018. P1 then moved back to 4D to look after his mother, leaving P2, his son, daughter‑in‑law and grandchild at the rented flat. Because 4D Master Room still had a strong smell, P1 and his mother both slept in the living room. P2 continued to live at the rented flat but returned to 4D every day to do housework and care for P1’s mother.

41.  On 8 August 2019, P1 heard a loud noise and discovered that concrete had fallen from the ceiling of 4D Master Bath, damaging the toilet bowl. He estimated the damaged area to be about 80 cm by 60 cm and 3 to 4 cm thick. He immediately notified the building management, who attended and took photographs, and he also informed the Joint Office.

42.  On 12 August 2019, staff from the Buildings Department inspected 4D. On 13 August 2019, the Joint Office confirmed that they had inspected 4D and found seepage at the ceiling of 4D Master Bath, but they had been unable to gain access to 5D for investigation. They told Ps that they had informed Ds that staff would be sent to 5D.

43.  On 3 October 2019, the Joint Office engaged another contractor to conduct further tests. On 17 October 2019, staff from the Buildings Department again inspected 4D. P1 was present and observed concrete spalling, exposed steel reinforcement and cracks in the ceiling of 4D Master Bath.

44.  On 23 December 2019, the Joint Office informed P1 that test results indicated defective waterproofing to the floor of the 5D Guest Bath, resulting in seepage affecting 4D Master Bath.

45.  On 5 February 2020, the Joint Office issued the 2020 Nuisance Notice to Ds requiring them to carry out repairs in 5D. On 17 March 2020, the deadline for compliance with the 2020 Nuisance Notice was extended to 30 June 2020.

46.  According to P1, as of 8 October 2020 seepage to 4D had still not ceased. Paint and concrete continued to spall from the ceilings, the cabinet remained damaged, and the Affected Rooms continued to emit a foul smell.

47.  Because the seepage problem persisted, Ps instructed Mr Leung to carry out further investigation. On 8 October 2020, Mr Leung inspected 4D and concluded that the Affected Rooms all showed signs of seepage and concrete/paint spalling. He opined that seepage in 4D originated from the water facilities of 5D Guest Bath.

48.  As P1 considers the seepage from 5D to be ongoing, he has not carried out any remedial works in 4D. He says there remains a risk of falling concrete and an unbearable odour, causing continuous disturbance since February 2017. He also says he has spent considerable time dealing with lawyers, the Joint Office, building management and experts. He complains that the seepage problem has troubled him and his family for six years without resolution and he asks the Court to do justice in his case.

F2.  The 1^st Defendant

49.  D1 and her husband, i.e. D2, have owned and lived in 5D since purchase in June 1991. The Mansion is over 55 years old and concrete has fallen from the ceilings of 5D and other flats in the Mansion. After Typhoon Mangkhut in September 2018, the IO carried out extensive external wall repair works between April 2019 and late 2020, including works to walls of flats D, E and F, which to D1 indicates that the external walls were defective before the repairs.

50.  Since around August 2017, Ps have repeatedly complained to D1 and to FEHD about alleged seepage from 5D to 4D. D1 says that until they appointed their expert in September 2022, she and D2 did not know whether these complaints were justified, but they tried to address them on the assumption they might be valid.

51.  After receiving the 2017 Nuisance Notice alleging seepage from 5D Master Bath, she immediately covered the floor drain outlet of 5D Master Bath in accordance with FEHD’s advice, and there were no further complaints or investigations about seepage from that drain pipe for about two years.

52.  Following the 2020 Nuisance Notice alleging seepage from 5D Guest Bath, D1 arranged two rounds of nano waterproof coating to the floor slab of 5D Guest Bath on 8 May 2020 and 18 June 2020, covering the entire floor area including the shower tray. She then instructed a contractor to carry out water ponding tests, after which she was told that P1 expressed satisfaction with the moisture readings at the ceilings of 4D Guest Bath and 4D Master Room.

53.  As FEHD continued to press for repairs to the floor slab of 5D Guest Bath, D1 says she engaged Creator again to apply a further waterproof layer to the floor of 5D Guest Bath on 28 July 2020, pending full slab works that were delayed by COVID‑19 and her husband’s health.

54.  In October 2020, D1 engaged Wing Fai to carry out full‑scale works to 5D Guest Bath pursuant to a quotation for HK$72,600, which included demolition of floor tiles, checking and (if necessary) replacing supply and drainage pipes, renewing the waterproof layer in the floor slab, and replacing the toilet.

55.  According to D1, when the tiles of 5D Guest Bath were removed, all original pipes (including fresh and waste) were found to be in good condition with no seepage, and he reported this to D1. D1 then instructed Wing Fai to proceed only with redoing the waterproof layer within the floor slab of 5D Guest Bath and other necessary non‑decorative works, leaving out re‑tiling and other cosmetic items. The works were carried out from 17 to 23 November 2020 and the final cost was $43,800.

56.  D1’s position is that, after these works, the waterproofing and pipework in 5D Master Bath and 5D Guest Bath were in good condition, and that there is no evidence that any residual seepage in 4D Master Bath, 4D Master Room or 4D Guest Room comes from the floor slab, walls or drainage pipes of 5D. She maintains that seepage from the external wall is a likely alternative cause.

F3.  Mr He Jiansheng

57.  Mr He is the proprietor of Wing Fai and has worked in property renovation including plumbing and electrical works for over 30 years.

58.  Mr He explains that in October 2020, D1 engaged him to carry out waterproofing works to 5D Guest Bath. He issued a quotation dated 25 October 2020 for $72,600 for removing the original floor tiles, checking original supply and drainage pipes, replacing the waterproof layer in the floor slab, replacing water pipes and the whole toilet, and related works. He estimated the works would take 8 to 12 working days and said he would carry out the works together with his company’s plumber.

59.  The works began on 17 November 2020. D1 initially believed that pipes in 5D Guest Bath might be leaking and thus wanted to redo the whole floor slab waterproofing, floor tiles and shower door, as set out in the quotation. However, after removing the existing tiles, he found all original pipes (both fresh water and drainage) were in good condition with no seepage. He informed D1 of his findings and, as a result, D1 instructed him only to redo the waterproof layer within the floor slab and necessary associated works, without carrying out other decorative works such as re‑tiling the floor.

60.  The works continued up to 23 November 2020. The final cost was reduced to $43,800.

G.  THE JOINT REPORT

61.  Pursuant to the Expert Directions, Mr Leung and Ms Lau jointly inspected 4D and 5D on 28 September 2022 (“First Joint Visit”) and the following tests were carried out:-

(a)  Visual inspections;

(b)  Dye water test at 5D Master Bath and 5D Guest Bath;

(c)  IR scan at 4D before and after the dye water test;

(d)  ECS at 4D before and after the dye water test;

(e)  Microwave scanning at 4D (by Ms Lau only);

(f)  Flow meter test at 5D (by Ms Lau only).

62.  On 28 October 2022, the Experts returned to 4D (“Second Joint Visit” and, together with the First Joint Visit, collectively referred to as “Joint Visits”) to inspect the condition of the ceilings following the dye water tests carried out at the First Joint Visit.

63.  Subsequently, Ms Lau issued her report dated 9 November 2022.

64.  On 1 December 2022, Mr Leung sent a draft report to Ms Lau (“2022 Leung Report (v.1)”) which was unsigned. On 16 December 2022, Ps’ solicitors sent a further report of Mr Leung (“2022 Leung Report (v.2)”), which was signed, to Ds’ solicitors. The test results in these two reports were the same but the conclusions were different. The changes in the conclusions were not drawn to Ds’ attention at the time.

65.  In the Joint Report, Ms Lau expressly pointed out that there was a difference between the 2022 Leung Report (v.1) and the 2022 Leung Report (v.2) but Mr Leung did not respond to that point.

66.  Ultimately, the 2022 Leung Report (v.2) was adopted by Mr Leung and enclosed with the Joint Report. In addition, Mr Leung annexed (a) the 2020 Leung Report and (b) the 2018 Pioneer Report to the Joint Report.

67.  In the Joint Report, which was signed by the Experts, they agreed that:-

(a)  There is mild and intermittent water seepage[5] affecting the ceiling of the Affected Rooms;

(b)  There is no seepage in 4D Room One; and

(c)  There is no leakage from the fresh water supply pipes of Flat 5D.

68.  However, they disagreed on the source of seepage at the Affected Rooms:-

(a)  Mr Leung’s opinion is that the waterproofing membrane beneath the shower tray in 5D Guest Bath is defective and leaking, and that the seepage has spread to the Affected Rooms[6];

(b)  Ms Lau’s opinion is that the is no evidence that the seepage at the Affected Rooms is related to 5D Guest Bath. In her view, the possibility that the seepage is related to seepage occurring at the external wall of the Mansion cannot be ruled out.

H.  PRINCIPLES ON EVALUATION OF EXPERT EVIDENCE

69.  As the outcome of this case largely turns on expert evidence, both Mr Leung and Ms Lau were extensively cross-examined.

70.  In his closing, Mr Fan put forward five fundamental propositions which, he submitted, guide the Court in evaluating the expert evidence which has been tested by cross-examination. They are as follows:-

(a)  Water does not only travel vertically down the concrete floor slab. It can also travel horizontally along points of weakness in the concrete. “Shortest distance” must be understood as the shortest distance along such weaknesses; Fung Hing Wang v Tang Chung Keung Raymond, HCA 189/2007, 7 March 2007 at §35; Tsang Sing Hung v Sack Yu Yeung, DCCJ 1316/2010, 2 May 2014 at §§153 & 175. Hence, there is no rule that the unit affected by seepage must necessarily be caused by the closest unit in terms of location. It is also for this reason there is no presumption that the water comes from the flat above;

(b)  It is well-known, and frequently observed, in water seepage cases that “[w]ater is notoriously able to find conduits to run along and to penetrate weak points some distance from its origin”; Yik Yuen Ling v Tso Wing Yan, DCCJ 813/2014, 18 October 2017 at §122; Chu Cheung Cheung v The IO of Provident Centre [2024] HKDC 1899 at § 131(9). Particularly in old buildings, water seepage is a “notoriously difficult problem” the “source and path of the leakage is difficult and sometimes impossible to identify”; Lam Suk Yee v The IO of Ka Kin Mansion [2018] HKCFI 2760 at  §120;

(c)  Cracks and weaknesses within concrete may not be apparent on visual inspection, whether at an external wall or elsewhere. Commentary recognizes that moisture paths can be “invisible to the naked eye”; Professional Guide to Water Seepage at §3.2.7;

(d)  For these reasons, visual observation is not a scientific or reliable means of determining the source of water seepage. Speculative reasoning based on “water travels the shortest distance” by looking at floor plans and excluding other flats separated by distance has been rejected as unscientific; Fung Hing Wang at §§24 & 35;

(e)  As regards IR and ECS scan, the raw numbers do not themselves identify the source of moisture. What matters is the professional interpretation and evaluation of the readings, including any changes before and after dye water tests. It is not a mechanical exercise of counting numbers; if it were, expert opinion would be unnecessary. In this case, the raw data relied on by the Experts are essentially the same; it is their interpretation which differs.

71.  Mr Fan emphasized that it is not for Ds to identify the source of seepage. The burden of proof does not lie with Ds. If, at the end of the trial, the source of seepage remains uncertain, the Court should dismiss the action.

72.  A defendant who can positively establish the true source of seepage will, of course, strengthen his case. But a failure to do so, or the Court’s rejection of an alternative source suggested by the defendant, does not relieve the plaintiff of the burden of proving its case by cogent and reliable analysis; Li Kuen Kwai Jay v Lok Chun Cheong [2019] HKDC 677 at §§98-99; Choy Shok Chun v Yu Hon Keung [2022] HKDC 671 at §§105-107 & 113-115, 119; Wong Pui Ping v Au Wai Ki Jacky, DCCJ 1225/2007, 17 April 2012 at §§99-106, 108-111.

73.  These principles reflect the inherent fact that water can travel in an almost infinite variety of ways, and that leakage paths are inherently difficult to detect. There is inevitably an element of evaluative judgment in choosing between competing hypotheses as to the source of seepage.

74.  Mr Fan further submitted that:-

(a)  Although the external wall (particularly in respect of rainwater) is sometimes an obvious potential source, water may travel in different directions and along paths that are not apparent to the naked eye; 

(b)  Under our adversarial system, the plaintiff has the prerogative to choose whom to sue. The Court’s directions as to testing will usually bind only the parties before it. A defendant will usually not be in a position to carry out tests in flats other than his own. There is therefore an inherent limitation on the scope of any investigation that the parties can undertake;

(c)  Previous cases have recognized the incidence of water seepage across floors or across units (through boundary walls), without any allegation against an intermediate “middle unit”; Hui Ling Chun v Shiu Mak Ying, DCCJ 10294/2001, 3 March 2004 at §143

(d)  The primary focus must therefore be on the expert opinions actually given and the tests they performed, and whether those opinions establish on a balance of probabilities that the alleged cause is indeed the true source of seepage.

75.  For these reasons, and as a matter of principle, it does not follow that, if there is insufficient evidence pointing to the external wall as a source, 5D must therefore be liable.

76.  I accept Mr Fan’s submissions, which are very thorough and persuasive, and I bear these principles in mind when evaluating the expert evidence.

I.  GENERAL CREDIBILITY OF EXPERTS

77.  Before turning to the content of the Joint Report, I must consider the general credibility of the Experts, in particular that of Mr Leung.

78.  As noted above, following the Joint Visits, Mr Leung produced two versions of his report, namely the 2022 Leung Report (v.1) and the 2022 Leung Report (v.2). Mr Fan pointed out that, although there was substantial overlap between them, some important matters were deleted or altered in the later version[7].

79.  When Mr Leung was asked why two different versions of his report had been sent to Ms Lau, he said that 2022 Leung Report (v.1) had not been sent by him personally. Instead, it had been mistakenly sent on 1 December 2022 by his staff member, Carson, who later followed up with an email dated 15 December 2022 asking Ms Lau to “ignore” it. However, Ps have not produced Carson’s email of 15 December 2022.

80.  Mr Leung was then asked whether he had been involved in the preparation of the 2022 Leung Report (v.1). Instead of answering the question directly, he said that he would not adopt that report. When pressed further, his answer was that he did not know. When it was put to him that the conclusions in the 2022 Leung Report (v.1) were written by him, he again replied that he did not know. When the differences between the conclusions in the two versions were drawn to his attention, Mr Leung repeatedly said that he had no comment.

81.  I am troubled by Mr Leung’s evidence concerning the two versions of his 2022 report, particularly the lack of any explanation for the change in conclusions.

82.  As Mr Fan submitted, and I accept, one important criterion in assessing the reliability of expert evidence is the expert’s impartiality and his adherence to his overriding duty to the court. An expert should not advance an argument or rely on information or data in support of his opinion unless he is professionally satisfied as to the validity of that argument and the appropriateness of that supporting material.

83.  Expert evidence is admitted to assist the court on matters requiring specialized expertise which the expert possesses but the court does not. What the court needs is the expert’s own independent professional opinion, not a partisan view constructed to advance a party’s case. The court must therefore be vigilant to ensure that the integrity of the process is not compromised by expert evidence given by someone who places a party’s interests above his professional duty to the court. If it can be shown that an expert persistently adopts a stance which he himself finds difficult to sustain, that is often the hallmark of a failure to comply with the duty of independence; Chinachem Charitable Foundation Limited v Chan Chun Chuen, HCAP 8/2007, 2 February 2010, §§483–489.

84.  I have great difficulty in understanding why Mr Leung could not answer the simple question whether he was involved in the preparation of the 2022 Leung Report (v.1). It is not uncommon for an expert to seek assistance from staff in preparing a first draft of his report, including the conclusions. If that were what happened here, there was no reason why Mr Leung could not frankly have said so and accepted that the 2022 Leung Report (v.1) was prepared by his staff, instead of giving the evasive answer “I do not know”. The reasonable inference from that evasive answer is that the conclusions in the 2022 Leung Report (v.1) were more likely than not written by Mr Leung himself. That, in turn, raises the more serious question why those conclusions then needed to be changed in the 2022 Leung Report (v.2). Mr Leung was given many opportunities to explain but repeatedly said that he had “no comment”. His failure to provide any satisfactory explanation for the change of conclusions casts doubt on his impartiality and independence.

85.  That said, although I have reservations as to Mr Leung’s impartiality and independence, I do not consider that his opinions should be rejected outright on this ground alone. In fairness to both parties, I shall proceed to examine the expert evidence. However, I will bear these concerns in mind when evaluating Mr Leung’s evidence and the weight to be attached to his opinions.

J.  EXPERT EVIDENCE

J1.  Mr Leung’s evidence

86.  As noted above, Mr Leung annexed the 2020 Leung Report and the 2018 Pioneer Report to the Joint Report. However, the site inspection for the 2020 Leung Report took place on 8 October 2020, before the 2020 Renovations in November 2020. For that reason, limited weight can be given to the test results in the 2020 Leung Report when assessing the position after the 2020 Renovations. The same applies to the 2018 Pioneer Report.

87.  In the 2022 Leung Report (v.2), it was recorded that:-

(a)  Dye water tests were carried out at various locations in 5D Master Bath and 5D Guest Bath for about 60 minutes[8];

(b)  IR scans of the Affected Rooms and Room One after dye water tests did not show any noticeable change[9];

(c)  ECS scans of the Affected Rooms and Room One after dye water tests did not show any significant change[10];

(d)  Fluorescent light scans of the Affected Rooms and Room One after dye water tests did not show any sign of dye[11];

(e)  There was no dripping at the ceiling of the Affected Rooms;

(f)  The wooden ceiling cabinet in 4D Guest Room got mouldy and blackened. There was a foul smell in that room.

88.  Mr Leung concluded that the source of seepage was 5D Guest Bath, essentially for the following reasons:-

(a)  ECS scan results:-

(i)  The ceiling of 4D Guest Room (at Locations 1, 4, 5 and 6) recorded moisture content higher than 20;

(ii)  The ceiling of 4D Master Room (at Locations 3, 5 and 6) recorded moisture content higher than 20;

(iii)  The ceiling at 4D Master Bath (at Locations 2, 4, 5, 6, 8, 9, 10, 11, 12, 14 and 18) recorded moisture content higher than 20;

(iv)  He considered this to indicate that there was still slight seepage at the ceilings of the Affected Rooms;

(v)  Among these, the ceiling area of 4D Master Bath with moisture content higher than 20 is close to the underside of the shower tray in 5D Guest Bath.

(b)  IR scan results:-

(i)  Mr Leung considered this to show that there was still a small amount of entrapped water at those ceilings, and that seepage was occurring at the ceiling of 4D Master Bath (close to the underside of the shower tray in 5D Guest Bath) and had spread to the ceiling of 4D Master Room;

(ii)  The wooden ceiling cabinet adjacent to the ceiling of 4D Guest Room (near 4D Master Room) was also found to be mouldy and blackened;

(iii)  It can therefore be inferred that the seepage at the ceiling of 4D Master Bath has spread to the ceilings of 4D Guest Room and 4D Master Room;

(c)  Rainfall data and external wall: Mr Leung referred to Hong Kong Observatory rainfall records to the effect that total rainfall in the week before the First Joint Visit was between 0 and 13.4 mm (with 13.4 mm recorded only on 23 September and 0 mm on the other days). He noted that the Experts nonetheless recorded moisture content higher than 20 and entrapped water at the ceilings of the Affected Rooms, and he considered this to indicate that seepage from the external wall was relatively unlikely. He also pointed out that no tests or water trials were conducted specifically on the external wall during the Joint Visits, and therefore said there was no evidence or indication of leakage from the external wall.

89.  For easy reference, the moisture content at the Affected Rooms is set out as follows (with Mr Leung’s highlights):-

(a)  4D Guest Room

Location	Before test	After test	Difference
1	21.0	21.2	+0.2 (9.5%)
2	14.9	14.9	-
3	16.1	17.4	+1.3 (8.07%)
4	22.5	24.1	+1.6 (7.11%)
5	21.0	21.7	+0.7 (3.33%)
6	20.1	20.6	+0.5 (2.49%)

(b)  4D Master Room

Location	Before test	After test	Difference
1	16.0	17.1	+1.1 (6.88%)
2	15.2	16.9	+1.7 (11.18%)
3	20.3	21.1	+0.8 (3.94%)
4	16.4	17.8	+1.4 (8.54%)
5	20.2	22.7	+2.5 (12.38%)
6	20.5	22.8	+2.3 (11.22%)

(c)  4D Master Bath

Location	Before test	After test	Difference
1	19.2	19.3	+0.1 (0.52%)
2	21.8	24.7	+2.9 (13.30%)
3	15.7	16.7	+1.0 (6.37%)
4	25.9	28.5	+2.6 (10.04%)
5	27.1	28.2	+1.1 (4.06%)
6	24.4	24.2	-0.2 (0.82%)
7	15.1	17.2	+2.1 (13.91%)
8	20.9	20.6	-0.3 (1.44%)
9	26.5	27.8	+1.3 (4.91%)
10	37.9	39.8	+1.9 (5.01%)
11	22.8	32.1	+9.3 (40.79%)
12	35.1	35.2	+0.1 (0.28%)
13	16.3	17.2	+0.9 (5.52%)
14	23.4	23.4	-
15	11.0	12.2	+1.2 (10.91%)
16	12.6	13.1	+0.5 (3.97%)
17	13.5	13.8	+0.3 (2.22%)
18	20.1	21.7	+1.6 (7.96%)

90.  During cross-examination, Mr Leung accepted, in essence, that:-

(a)  No single test should be viewed in isolation. The results of different tests should be interpreted together and compared;

(b)  The IR results obtained at the First Joint Visit on 28 September 2022 showed no change before and after the dye water tests. In other words, they did not show that seepage in the Affected Rooms originated from 5D;

(c)  The ECS results by themselves show only the moisture content at the surface, or very close to the surface. The 18 locations referred to and highlighted in 2022 Leung Report (v.2) (“Highlighted Points”) were highlighted not because of any comparative differences before and after the dye water tests, but because the moisture readings were above 20, which he treated as indicating the presence of seepage;

(d)  The increase of 9.3 (from 22.8 to 32.1) at Location 11 of 4D Master Bath was described by him as “slight”, and still below the 35% moisture benchmark which the Joint Office treated as indicative of obvious water seepage;

(e)  It was the analysis of the general trend in the readings that was important, rather than one or two isolated locations. In re‑examination, Mr Leung further said that there was no particular value in focusing on a single location;

(f)  Cracks within a floor slab or external wall may not be visible on surface inspection; and

(g)  Water may flow in different directions within a slab depending on the pattern of cracks.

J2.  Discussions

91.  Having considered Mr Leung’s evidence, I am of the view that his conclusion that 5D Guest Bath is the source of seepage is fundamentally flawed.

92.  First, the fact that the moisture content at a particular location exceeds 20 shows only that there is seepage at that location. It does not, by itself, shed any light on the source of that seepage. Likewise, the fact that some of the Highlighted Points happen to be close to the shower tray of 5D Guest Bath cannot prove that the shower tray is the source of seepage. As Mr Leung himself accepted, water can travel in different directions within a slab depending on the pattern of cracks, and one should not jump to the conclusion that water must have come from the upper unit simply because seepage is observed at the ceiling.

93.  Mr Leung also accepted that what really matters, so far as the ECS readings are concerned, is the change in moisture content at the test locations before and after the dye water test at 5D Guest Bath, particularly at the Highlighted Points, where the readings were already high. If 5D Guest Bath were indeed the source of seepage, one would expect to see a general increase in moisture content across the ceilings of the Affected Rooms after that test.

94.  However, the 2022 Leung Report (v.2) contains no comparative analysis of the changes in moisture content before and after the dye water test, still less any analysis as to whether those changes exhibit a general trend. The changes set out in paragraph 89 of this Judgment were in fact calculated by the Court and the percentage figures in brackets were first set out by Ms Yang in her closing submissions.

95.  Secondly, it is common ground in the Joint Report that there was no seepage in Room One. However, as recorded in the 2022 Leung Report (v.2), there were nevertheless changes in moisture content at the ceiling of Room One and the changes are set out as follows:- 

Location	Before test	After test	Difference
1	9.0	11.3	+2.3 (25.55%)
2	10.4	13.4	+3.0 (28.84%)
3	9.7	10.5	+0.8 (8.24%)
4	16.4	17.5	+1.1 (6.71%)
5	13.7	14.3	+0.6 (4.38%)
6	11.5	12.4	+0.9 (7.82%)
A	16.6	18.4	+1.8 (10.84%)

96.  It is particularly noted that the percentage changes at Locations 1 and 2 in Room One exceeded 25%, which is higher than the changes at all locations in the Affected Rooms, save for Location 11 at 4D Master Bath. If moisture content in a room with no seepage can fluctuate to that extent, it materially undermines any attempt to rely on the comparatively smaller changes in the Affected Rooms to prove a relationship between the dye water test and the moisture changes.

97.  Faced with this difficulty, Mr Leung then sought to resile from the common ground that there was no seepage in Room One, and claimed instead that Room One was in fact affected by water seepage and that the Joint Report was inaccurate. He purported to explain that he had said there was no seepage in Room One only because none of the locations there recorded a moisture content higher than 20 (which was the benchmark he had adopted to highlight locations in the Affected Rooms).

98.  I do not accept Mr Leung’s evidence that Room One was affected by water seepage. In my view, there is a fundamental difference between “no seepage” and “with seepage but not serious”, and it cannot seriously be suggested that Mr Leung did not appreciate that distinction.

99.  Further, under the Expert Directions, the experts’ duty was to give evidence “on liability and quantum regarding the alleged water seepage / leakage at the ceiling of [4D], namely the source and extent of water seepage / leakage (if any) …”. There was nothing to prevent Mr Leung from stating, in either his own report or the Joint Report, that Room One was affected by seepage but that the extent was not serious because the moisture content there was below 20. His failure to do so sits ill with his belated attempt to suggest that Room One was in fact subject to seepage.

100.  Thirdly, while Mr Leung relied on the IR scan results to support his conclusion that there was seepage at the ceilings of 4D Master Room and 4D Master Bath (a fact which is not in dispute), he did not explain how those IR scan results supported his conclusion that 5D Guest Bath was the source of that seepage. Apart from repeating the same argument that some of the Highlighted Points were close to the shower tray of 5D Guest Bath, he offered no reasoning linking the IR results to the alleged source.

101.  On the contrary, in the 2022 Leung Report (v.2), Mr Leung expressed the view that the IR scan results did not show any noticeable change. That view is the same as Ms Lau’s and it was not challenged by Ms Yang.

102.  In other words, Mr Leung’s conclusion that 5D Guest Bath is the source of seepage does not sit well with both the IR results (which showed no noticeable change) and the dye water test results (no dye water was found at the Second Joint Visit). Mr Leung made no attempt to reconcile or explain this inconsistency.

103.  Fourthly, another plank of Mr Leung’s reasoning is that the chloride and ammonium tests conducted on specimens taken from the Affected Rooms on 8 October 2020 both yielded positive results.

104.  Mr Leung explained that if the seepage originated from the sewage system, the chloride and ammonium readings would be very high whereas if it came from the freshwater system, the chloride and ammonium tests should be negative. On that basis, he considered that the seepage came from shower water which normally contains small trace of sweat and urine.

105.  However, no chloride or ammonium tests were carried out during the Joint Visits in 2022. When asked why he had not proposed that the same tests be repeated in 2022, Mr Leung’s answer was that he was confident in his conclusion and therefore saw no need to perform chloride and ammonium tests again.

106.  With respect, I do not follow Mr Leung’s logic. Conclusions should be reached after evaluating the results of all appropriate tests, not before. If, as he considered in 2020, chloride and ammonium testing was a helpful tool in identifying the source of seepage, one would reasonably expect him to propose to Ms Lau that the same test be conducted during the Joint Visits. To say that further testing was unnecessary because he was already sure of his conclusion is, in my view, to put the cart before the horse and tends to suggest that Mr Leung was working towards a pre‑determined conclusion.

107.  During cross‑examination, Mr Leung also sought to expand the reasons for his reliance on the ECS results to support his conclusion. He said that the mere fact that the moisture content at some of the Highlighted Points increased after the dye water test was, by itself, analytically significant. In re‑examination, he went further and suggested that one could discern a “general trend” by comparing the average moisture content of all locations in the Affected Rooms before and after the dye water test.

108.  As Mr Fan rightly pointed out, this line of reasoning appears in neither of Mr Leung’s reports nor in the Joint Report. It was advanced for the first time only when he was under cross‑examination.

109.  Mr Fan submitted that the law has consistently set its face against an expert introducing a new point of substance or “moving the goalposts” only at trial, and that the Court should give little or no weight to matters mentioned for the first time in oral evidence; Sun Cheong Construction Co Ltd v The Incorporated Owners of King Fu, Ho Fu, Ki Fu & Ka Fu Buildings [2019] 5 HKC 210[12] at §12. I agree, and consider that Mr Leung’s belated explanation only serves to further undermine his credibility as an expert witness.

110.  Leaving the issue of “lateness” aside, Mr Leung’s “new” methodology still cannot explain the moisture changes in Room One. For instance, the average change of moisture content in Room One was 1.5 which is comparable to the corresponding changes in 4D Master Room (1.63) and 4D Master Bath (1.46), and much higher than 4D Guest Room (0.71). If one compares the average percentage change in moisture content, Room One’s change of 13.2% is in fact much higher than the corresponding changes in all of the Affected Rooms; 4D Guest Room (3.66%), 4D Master Room (9.02%) and 4D Master Bath (7.08%).

111.  I have not overlooked Location 11 at 4D Master Bath, where the moisture content increased by 9.3 (or about 40%) after the dye water test. However, as Mr Fan correctly pointed out, Mr Leung did not single out this location in his own report, still less highlight any particular significance in that change. Location 11 was included among the Highlighted Points solely because its pre‑test moisture content exceeded 20 and had nothing to do with the magnitude of the subsequent increase.

112.  Moreover, it is Mr Leung’s evidence that the reading at a single location has no reference value and that one should look at the pattern of points generally. He further accepted that it was possible that the significant change at Location 11 was due to migration of moisture from adjacent Locations 10 and 12, which already had high pre‑existing moisture contents of 37.9 and 35.1 respectively.

113.  I therefore accept Mr Fan’s submission that Location 11 is an outlier among all the locations in the Affected Rooms. Its result does not sit well with the IR results, which show no apparent change in readings, in particular in respect of 4D Master Bath. It does not assist Mr Leung in reaching his conclusion.

114.  Ms Yang devoted a considerable part of her closing submissions to persuading the Court to accept Mr Leung’s conclusion. While I appreciate Ms Yang’s effort, I am unable to accept her submissions for the very reason that they do not overcome what I regard as the fundamental problem with Mr Leung’s conclusion, namely that the various test results on which he relies are themselves inconsistent and conflicting.

115.  Nor does Ms Yang’s reliance on the nuisance notices, contractors’ reports and similar materials assist her. As noted above, there is no dispute that Ds carried out the 2022 Renovations in November 2022. Documents which relate to the situation prior to those renovations have, in that sense, been overtaken by events.

J3.  Ms Lau’s evidence

116.  In her closing, Ms Yang attacked the evidence of Ms Lau and submitted that there are a number of discrepancies in it:-

(a)  In the Joint Report, the Experts agreed that there was mild and intermittent seepage on the ceiling of the Affected Rooms. In oral evidence, however, Ms Lau sought to clarify that the intermittent seepage only occurred in the ceiling of 4D Master Room, but not in 4D Master Bath or not 4D Guest Room;

(b)  In her own report, Ms Lau concluded that there was no apparent change in ECS test. Ms Yang submitted that this was inconsistent with the fact that many locations in the Affected Rooms showed changes in moisture content of more than 5%, which, she argued, could not properly be described as “minor” changes; and

(c)  Under cross‑examination, Ms Lau said that water penetrating from the external wall could come from air‑conditioners. Ms Yang submitted that air‑conditioners were not mentioned in Ms Lau’s report and that this was raised for the first time at trial. She also pointed out that Ms Lau accepted in her report that she had not observed any apparent damage or sign of water seepage from the external wall outside 4D and 5D.

117.  With respect, I do not accept Ms Yang’s submissions:-

(a)  Whether seepage can properly be described as “intermittent” is a matter of evaluative judgment, depending on the frequency and seriousness of the episodes of seepage. Ms Lau’s attempted clarification in oral evidence does not, in my view, materially detract from the common ground that the seepage in the Affected Rooms was mild and intermittent;

(b)  Likewise, whether a change of more than 5% in moisture content can be regarded as “minor” is also a matter of judgment, and it cannot be said that Ms Lau was plainly wrong in concluding that there was no apparent change in the ECS results after the dye water test. More importantly, the ECS readings were already fully set out in the experts’ respective reports and in the Joint Report, and it was always open to the parties to make submissions based on those underlying data;

(c)  As to the air‑conditioners, while it is correct that Ms Lau did not expressly refer to them in her report, she did identify the external wall as a possible source of seepage. Her reference in cross‑examination to water from air‑conditioners is, in substance, no more than an elaboration of that opinion, offering a possible mechanism by which water could reach the external wall. It does not amount to any material inconsistency with her written evidence.

118.  I therefore do not regard these matters as significantly undermining Ms Lau’s evidence.

119.  More importantly, the Court is not bound to choose between the evidence of Mr Leung or Ms Lau. Even if the Court decides to reject Ms Lau’s evidence as invited by Ms Yang, it does not necessarily mean that the Court must accept Mr Leung’s evidence.

J4.  Conclusion on expert evidence

120.  By reason of the matters set out above, I reject Mr Leung’s evidence and prefer Ms Lau’s evidence in so far as it relates to the alleged source of seepage from 5D.

121.  For the avoidance of doubt, I confirm that I have considered all of Ms Yang’s submissions, both opening and closing, together with all the evidence on which she relied. I do not consider it necessary, however, to deal expressly with each and every point she raised, so as not to add unnecessarily to the length of this judgment.

122.  I also wish to make it clear that I make no finding on whether the external wall is, or is not, the source or one of the sources of seepage. Whilst I very much hoped to find the source of seepage, it is regrettable that there is insufficient evidence for me to reach any concluded view.

123.  Although I have great sympathy for Ps’ situation, I agree with Mr Fan that sympathy is no shortcut to proof. In light of my conclusions on the expert evidence, I must find that Ps have failed to discharge their burden of proof that 5D Guest Bath was the source of seepage in the Affected Rooms.

K.  RELIEF

124.  In light of my conclusion on liability, it is not strictly necessary for me to deal with quantum or relief. I nevertheless do so briefly, in case I am wrong on liability.

125.  As regards the costs of repair, Mr Fan fairly accepted that, if liability had been established, Ds would not dispute Mr Leung’s estimate of $56,819.

126.  As to damages for nuisance, distress, discomfort and inconvenience, Ms Yang submitted that Ps’ claim of $100,000 is reasonable whereas Mr Fan submitted that a sum of $70,000 would be appropriate.

127.  There are no hard and fast rules, and the parties’ conduct is relevant; Cheng Suk Lai v Wong Man Fai [2024] HKDC 1500 at §155. When considering the appropriate amount, I take into account the following:-

(a)  The seepage problem started in 2017;

(b)  Ds could not be regarded as “uncooperative throughout” as it is not disputed that Ds did carry out various repair works;

(c)  The 2020 Renovations were delayed by reason of COVID-19 and D2’s health conditions. Applications had been made by Ds and extension had been granted for compliance of the 2020 Nuisance Notice;

(d)  The claim is for P1 and P2. The situation of P1’s mother, son and daughter-in-law is irrelevant; and

(e)  There is no medical evidence showing that P1’s alleged health issues were caused by the seepage.

128.  Having considered all other relevant factors in the present case, I am of the view that the reasonable amount is $80,000. I further award interest on the general damages at the rate of 2% per annum from the date of writ, and thereafter at judgment rate.

129.  For injunction, I agree with Mr Fan that it must be formulated precisely and clearly so that Ds know what they must do and what steps they must take; Tech Focus Ltd v Austria Property Management Ltd [2004] 1 HKC 343 at §2. In water seepage case, the usual remedy is a mandatory injunction to effect due repairs of the parts identified to be defective; Chiu Hung Shun Paul v So Ka Tai, CACV 136/2005, 5 December 2005 at §16.

130.  Therefore, if liability is established, I would make an order that Ds, by themselves, their servants or agents or otherwise, shall carry out all necessary rectification, repair and/or remedial works to the waterproofing membrane of the shower tray in 5D Guest Bath to stop or prevent water seepage from 5D Guest Bath to the Affected Rooms in 4D within 60 days from the date of this Judgment.

L.  CONCLUSION

131.  By reason of the aforesaid, I dismiss Ps’ claim against Ds.

132.  Costs should follow the event. I make an order nisi that Ps do pay Ds’ costs of this action, including any costs reserved, to be taxed if not agreed, with certificate for counsel. Any application to vary the costs order nisi should be made within 14 days from the date of this judgment.

133.  I thank counsel, particularly Mr Fan, for their assistance to the Court.

ANNEX