WA Rental Property Habitability: Ventilation, Mould, and Heating Requirements

WA doesn't have a checklist of mandatory habitability features the way Victoria has for minimum heating standards. Instead, Section 42 of the Residential Tenancies Act 1987 creates a broad duty: the property must be in a reasonable state of repair and fit for human habitation, considering its age, character, and prospective life. That general standard covers ventilation, dampness, mould, and thermal comfort — but the boundaries aren't always obvious.

Ventilation

Dwellings must have adequate openable windows or mechanical exhaust systems in moisture-prone rooms — bathrooms, laundries, and kitchens. If a bathroom has no window and no exhaust fan, that's a structural deficiency that falls on the landlord.

The standard doesn't require air conditioning or forced ventilation throughout the property. But if rooms can't be ventilated at all — sealed windows, no fans, no openable sashes — the property doesn't meet the habitability baseline.

Mould: Who's Responsible

Mould disputes are one of the most contested issues in WA tenancies, and the liability split comes down to cause:

The landlord is responsible when mould stems from:

• Structural defects (rising damp, cracked walls)
• Inadequate built-in ventilation (no exhaust fan where needed)
• Plumbing failures or water ingress
• Roof leaks

The tenant is responsible when mould results from:

• Failure to use provided exhaust fans
• Drying clothes indoors without ventilation
• Inadequate routine cleaning

In practice, proving the tenant caused the mould requires evidence that the property's ventilation was adequate and the tenant failed to use it. If the bathroom has no exhaust fan and the mould is concentrated there, the structural argument favours the tenant.

Heating and Thermal Comfort

As of October 2026, WA has no mandatory minimum thermal performance ratings, ceiling insulation requirements, or energy efficiency disclosure schemes for private rental properties.

The National Construction Code mandates insulation and thermal performance for new construction and major renovations — but those standards don't apply retroactively to older existing rentals.

What the landlord does owe:

• If you supply heating or cooling appliances (space heaters, air conditioners, ceiling fans, evaporative coolers), you must keep them in safe, functional working order under the general maintenance duty
• Failure of a supplied heating or cooling system during extreme weather needs to be addressed within reasonable timeframes
• WA has no general statutory requirement to install heating in every rental; the general Section 42 habitability duty still applies

Phase Two reform proposals have raised the idea of codified minimum thermal standards, but nothing has been enacted.

Water Supply and Hot Water

The property must have continuous access to a potable water supply and a functioning hot water system delivering hot water to kitchen, bathing, and laundry facilities. A complete hot water failure is classified as an essential service under the RTA — the 24-hour repair window applies.

In regional areas where mains water isn't available, tank water systems must be structurally sound and the landlord maintains the pump and tank. If filtration is needed for potability, that's on the landlord too.

For the complete habitability framework alongside every WA safety and compliance obligation, get the landlord compliance guide.

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