Mould in a strata apartment triggers one of the most complex disputes in residential property, the question of whether the mould is caused by a common property defect (owners corporation’s responsibility) or a lot-specific issue (the lot owner’s responsibility). In Wollongong’s growing high-rise and townhouse strata sector, from the CBD apartments and Northbeach precinct to the townhouse complexes of Dapto, Shellharbour, and Kiama, this dispute plays out regularly, often with significant financial and health consequences for lot owners caught in the middle. This guide gives lot owners the legal tools to identify responsibility, document their position, and force action. See also our strata mould overview and strata insurance guide.
Quick Answer (BLUF)
Under the Strata Schemes Management Act 2015 (NSW), the owners corporation is responsible for maintaining common property (external walls, roof, balconies, shared drainage). If mould in a lot is caused by a defect in common property, the owners corporation must fix it. Lot owners have the right to request repairs in writing, attend general meetings to push for action, and apply to NCAT if the owners corporation fails to meet its obligations.
Step 1, Establish Who Is Responsible
The first, and most contested, question in any strata mould dispute is whether the mould source is common property or lot property.
Common property (owners corporation’s responsibility):
- External walls and cladding
- Roof structure and waterproofing
- Shared drainage and stormwater systems
- Balcony waterproofing and balustrades (varies by scheme, check your strata plan)
- Shared walls between lots (depending on the boundary definition in the registered strata plan)
- Window frames and seals in some schemes, check the strata plan
Lot property (lot owner’s responsibility):
- Internal walls and internal surfaces
- Bathroom waterproofing within the lot (shower, bath)
- Plumbing within the lot (pipes not serving multiple lots)
- Internal HVAC systems
- Any alterations made by a previous owner without approval
The boundary between lot and common property in a Wollongong high-rise can be complex, the registered strata plan is the definitive reference. Many Wollongong CBD apartment buildings (particularly those built in the 1990s, 2000s) have strata plans that draw the boundary at the internal face of the external wall, meaning the external wall cavity and external cladding is common property but the internal plasterboard is lot property.
The practical test: A professional mould inspection with moisture metering and thermal imaging can identify where moisture is entering and trace it to its source, this is essential evidence in any responsibility dispute.
Step 2, Document Your Position
Before engaging the owners corporation, build your evidence base:
- Photographs with date stamps showing the mould, its location, and extent
- Written records of all previous reports to the owners corporation or strata manager (emails, meeting minutes)
- A professional inspection report identifying the source of moisture and whether it is consistent with a common property defect
- Any relevant strata records, building reports, previous repair history for the affected area (available by requesting strata records search or at general meetings)
- Medical documentation if the mould is affecting your or your family’s health
Step 3, Formal Written Request to the Owners Corporation
Lodge a formal written request with the owners corporation (via the strata manager) that:
- Describes the mould, its location, and the impact on your lot
- Identifies the probable cause (common property defect, e.g., failed external wall waterproofing, blocked roof drainage)
- Attaches your inspection report and photographs
- Requests a response within 14 days and specifies the repair required
- States that you will seek NCAT orders if the owners corporation fails to act
Under the Strata Schemes Management Act 2015, the owners corporation must consider and respond to maintenance requests. A failure to respond, or an inadequate response, creates the basis for a NCAT application.
Step 4, Raise It at a General Meeting
If the strata manager is unresponsive, request that the matter be placed on the agenda of the next general meeting of the owners corporation. As a lot owner, you have the right to:
- Attend and participate in general meetings
- Raise matters from the floor
- Put motions for the owners corporation to commission an inspection report or approve a repair budget
General meeting resolutions on ordinary repair matters require a simple majority. If other owners are affected by the same building defect (common in Wollongong’s older residential towers where external waterproofing failures affect multiple floors), you may find other lot owners with the same grievance willing to support a repair motion.
Step 5, Apply to NCAT if the Owners Corporation Fails to Act
The NSW Civil and Administrative Tribunal has jurisdiction over strata disputes under the Strata Schemes Management Act 2015. You can apply to NCAT for:
- An order compelling the owners corporation to carry out specified repairs to common property
- An order for the owners corporation to pay compensation for loss or damage caused by their failure to maintain common property
- An order for an investigative inspection of common property at the owners corporation’s cost
The NCAT Strata and Community Schemes division is the correct division for these applications. Filing fees apply ($97.50 for an application as at 2025).
Your professional inspection report will be a key exhibit in any NCAT application. An assessor who can explain, in plain language, the causal relationship between a common property defect and the mould in your lot will be invaluable at a hearing.
Special Case: Building Defects in New or Recent Constructions
In Wollongong’s newer strata buildings, particularly those in the 2000s, 2020s construction boom, building defects (waterproofing, cladding, drainage) are a significant source of mould in individual lots. These cases add an additional layer:
- The owners corporation may have a claim against the builder (or developer) for the defect under the Home Building Act 1989
- The major defect warranty period is 6 years from practical completion
- Mould caused by a waterproofing defect in a common area is a classic “major defect”
- The owners corporation should be engaging a building solicitor and defect assessor, if it is not, as a lot owner you can push for this through general meeting motions
FAQs
What if the strata manager tells me the mould is my responsibility but I believe it is from a common property defect?
Do not accept this position without an independent assessment. Strata managers are not mould or building experts, and determining the source of moisture requires a qualified assessment. Obtain an independent report from a credentialled mould assessor, if it identifies a common property defect as the cause, you have the evidence to challenge the strata manager’s position.
Can I carry out mould remediation myself and seek reimbursement from the owners corporation?
Proceeding with remediation and then seeking reimbursement is high-risk, if the owners corporation disputes the amount or the allocation of responsibility, you may not recover costs. The better approach is to first establish responsibility through NCAT if necessary, then have the owners corporation arrange and fund the remediation directly.
Does strata building insurance cover mould damage in my lot?
It depends on the cause and the policy. Mould resulting from a sudden insured event (burst pipe, storm) is typically covered under the strata building policy. Mould from gradual moisture ingress through a building defect is often excluded. See our strata insurance guide and insurance denial appeal guide for more detail.