Mould in Rental Properties: NSW Landlord and Tenant Obligations
Mould in a rental property raises questions about who is responsible for fixing it. Here is how NSW tenancy law approaches the issue and when a professional assessment helps resolve disputes.
Mould in a rental property is a common source of dispute between landlords and tenants. Both parties often have a genuine belief that the other is responsible, and the reality is that responsibility depends on the cause, which is not always straightforward to determine without a professional assessment.
This article outlines how NSW tenancy law approaches mould, what landlords and tenants are each responsible for, and when a professional inspection can help resolve the situation.
The general framework under NSW law
The Residential Tenancies Act 2010 (NSW) requires landlords to provide and maintain a rental property in a reasonable state of repair, having regard to the age and character of the property. This includes ensuring the property is fit to live in.
Amendments that came into effect in 2023 introduced minimum standards for rental properties, including requirements related to ventilation. Properties must have windows or skylights in habitable rooms that can be opened, and exhaust fans or openable windows in bathrooms and laundries.
Tenants are required to keep the property reasonably clean and to notify the landlord promptly of any damage or need for repairs.
When the landlord is generally responsible
A landlord is generally responsible for mould that results from a structural defect or maintenance issue with the property. Common examples include:
- A roof leak that allows water to enter the building
- Plumbing leaks inside walls or under floors
- Failed waterproofing in a shower or bathroom
- Inadequate ventilation that cannot be addressed by the tenant (for example, a bathroom with no exhaust fan and no openable window)
- Rising damp through the slab or footings
- Blocked or damaged gutters that allow water to pool against the building
In these situations, the mould is a consequence of a property defect that the landlord is responsible for repairing. The landlord should arrange for the defect to be fixed and for any resulting mould to be professionally remediated.
When the tenant may bear some responsibility
Tenant behaviour can contribute to mould growth, particularly in properties that are otherwise structurally sound. Examples include:
- Not using exhaust fans or opening windows during and after showering
- Drying washing indoors without adequate ventilation
- Leaving spills or water damage unaddressed
- Not reporting a leak or maintenance issue promptly, allowing moisture damage to worsen
Where mould has developed primarily because of tenant behaviour rather than a property defect, the tenant may bear some or all of the responsibility for remediation costs.
In practice, responsibility is often shared. A property with marginal ventilation may develop mould more readily if the tenant does not use available ventilation, but the landlord may still have an obligation to improve the ventilation to meet minimum standards.
The importance of identifying the moisture source
The key to resolving a mould dispute is identifying the moisture source. Without that information, it is difficult to determine whether the mould is the result of a property defect or tenant behaviour, or both.
A professional mould inspection will assess:
- The location and extent of mould growth
- Moisture levels in building materials
- Whether there is evidence of structural water ingress (leaks, rising damp, failed waterproofing)
- Whether ventilation is adequate for the property
The written report provides an objective record of the findings that both parties can use to understand the situation and, if necessary, to support a claim at the NSW Civil and Administrative Tribunal (NCAT).
Practical steps for tenants
If you are a tenant dealing with mould in a rental property:
- Notify the landlord in writing as soon as you identify mould or a moisture problem. Keep a copy of all correspondence.
- Document the mould with photographs, including the date.
- Use available ventilation, exhaust fans, openable windows, and keep the property reasonably clean and dry.
- Follow up if repairs are not made within a reasonable time. If the landlord does not respond, you may be able to apply to NCAT for an order requiring repairs.
Practical steps for landlords
If you are a landlord dealing with a mould complaint:
- Respond promptly to the tenant's notification and arrange an inspection.
- Identify and fix the moisture source before arranging mould remediation. Treating mould without fixing the underlying cause will result in regrowth.
- Arrange professional remediation where the contamination is significant. Surface cleaning is not appropriate for mould that has spread into building materials.
- Keep records of all maintenance and remediation work carried out.
A professional mould inspection provides both parties with an objective assessment of the situation. If you need an inspection for a rental property in Greater Sydney or surrounding regions, contact Hazmat Detection & Removal.
