a. Factual and documentary evidence

a. Factual and documentary evidence 

Factual and documentary evidence serves to establish the existence, duration, and severity of the nuisance, often providing the factual basis required for expert deductions. 

1. Photographs and videos 

Contemporaneous visual records are considered powerful evidence of the physical state of a property. 

• Proof of damage: Photos and videos are essential to document specific signs of seepage, including water stains, dripping, bulging or peeling plaster, mould, and efflorescence (crystallised liquid/white powder). 
• Structural deterioration: They record more severe damage such as concrete spalling, cracks, and exposed or rusted steel reinforcement bars. 
• Duration and magnitude: A series of photos taken over several years can demonstrate that a problem is persistent or recurring, which is vital for assessing general damages. 
• Specific incidents: Video clips can capture active drippage, such as water leaking from an air-conditioning installation or a specific ceiling point, which helps distinguish between different potential sources. 
• Comparative evidence: Photos taken before and after a dye test or heavy rainfall provide a visual baseline to determine if moisture levels have worsened or if dyed water has appeared. However, courts have noted that the cause of seepage cannot be addressed based on a single photograph alone without site inspections or tests. 
• Limitations: While photos prove the condition, they generally cannot identify the source or cause of seepage on their own without site inspections or technical tests. Furthermore, differences in photo colouring (e.g. a “yellowish” tint in prints) can sometimes be mistaken for deterioration when they are actually printing artefacts. 

2. Witness statements 

Witness statements help explain how the seepage affected the occupiers in practice and provide context that may not be apparent from documents or photographs alone. 

• Occupants and owners: Statements from owners or tenants describe the timing and frequency of the seepage (e.g. if it occurs only after rain) and the resulting discomfort, such as the need to place buckets to catch water or the presence of foul odours. 
• Reliability and credibility: Courts closely scrutinize witness credibility. For instance, a witness may be deemed less reliable if he has not personally resided in the flat during the material times or if their statement is flatly contradicted by objective records. 
• Technicians and plumbers: Workers who attended the premises shortly after a leak began can testify to immediate findings, such as a burst pipe in a cabinet or a collapsed false ceiling. 

3. Utility bills and weather data 

Utility bills and weather data can assist in identifying patterns and possible causes of seepage, particularly where the source may involve plumbing defects or rainwater ingress. 

• Wastage of water: Drastic changes in water consumption records or letters from the Water Supplies Department noting “wastage of water” may support claims of supply pipe leakage. 
• Irrelevance of low consumption: Conversely, low or negligible water consumption in a suspected upper flat may weaken an allegation of an active supply pipe leak, but it may not be decisive and may be irrelevant if the alleged source is not tied to water usage. 
• Weather data: Hong Kong Observatory records are crucial for establishing causation related to external walls or roofs. A correlation between rainfall and seepage intensity strongly suggests a building envelope defect rather than an internal pipe leak. 

4. Management records 

Management records are useful because they are usually created contemporaneously by the management office or property management company. These entities may be relatively independent of the immediate dispute and may show the history of complaints, inspections, and responses. 

• Incident reports: Management office records, such as Security Incident Reports, document the initial discovery of flooding or leakage and identify immediate suspected sources like a burst flush water pipe. 
• Demand letters and correspondence: A series of demand letters from the management office to an owner to resolve seepage issues serves as evidence of actual knowledge on the part of the defendant. 
• Technical logs: Management office staff often perform preliminary moisture tests which are recorded in their internal logs. 
• Incorporated Owners’ minutes: Minutes from Management Committee meetings may document a history of complaints and the progress (or lack thereof) of remedial works. 

5. Statutory enforcement evidence 

Investigative records and correspondence produced by government departments carry significant evidentiary weight in court. Because these records are compiled by public officers acting as neutral, contemporaneous investigators, courts generally accord them substantial, albeit not conclusive, weight. 

• Joint Office’s evidence: Formal reports and Nuisance Notices issued by the Joint Office for Investigation of Water Seepage Complaints are highly persuasive, as they are compiled by independent agents using standard testing procedures. 
• Repair notices: Official repair notices issued by the Water Supplies Department may be strong evidence that a plumbing defect existed or was suspected in a particular unit, although further evidence may be required to prove that the defect caused the seepage complained of. 

6. Evidence for damages 

Evidence of damages is required to quantify the financial loss suffered and to support any claim for compensation, reinstatement costs, or health-related harm. 

• Tenancy agreements and rent records: Necessary to prove rental loss or the need for rental reductions due to the appalling condition of the premises. 
• Repair quotations and invoices: Used to establish the cost of reinstatement. 

• Medical records: Required if a plaintiff claims health conditions (like skin problems) were caused by the damp environment.