Mould and Residential Tenancies: Everything You Need to Know

surface sample of mould growth on further

What is Mould?

Mould is a type of fungus that can be found in damp environments. It is a problematic substance for buildings and homes because it can spread quickly and cause a lot of damage.

Mould is also often associated with the smell of earthy, musty odours which are noticeable from a few meters away from the building or home.

It is important to be able to identify mould so you know what you are dealing with and how to get rid of it. There are different types of mould, all requiring different treatment methods.

Some molds may not seem very dangerous but still have an effect on our health or on our homes’ structure if left untreated for too long.

How Does Mould Spread and How Do You Recognise It?

Did you know that one (1) in three (3) homes in Australia has mould growth? The key to preventing the spread of mould is to act on the early signs.

Mould spreads by producing microscopic spores, which can travel through air and settle in places where they find the right conditions to grow.

Mould looks like different colours, depending on what it is made of. There are many kinds of moulds, but most are black or greenish-black.

Mould creates volatile organic compounds (VOCs) which create smells and odours. Typical smells are musty or earthy. When left untreated, mould may also cause respiratory problems, allergies and other issues.

mould sampling on ceiling

Tenants Rights and Obligations

Tenants have certain rights and obligations which are defined by the Residential Tenancies Act 2010. This law ensures that tenants have a safe and secure place to live.

The Residential Tenancies Regulation 2019 defines what a tenant’s obligations are in regards to what they can do or not do in the property. It also defines the required standard of cleanliness and maintenance for rental properties.

The landlord is also required to provide a home that is fit for habitation, structurally sound and kept in reasonable repair.

For more information, here’s a mould factsheet from

Minimum Standards Checklist

The Residential Tenancies Regulation 2019 has a minimum standards checklist for you to use before signing the tenancy agreement.

The landlord must indicate whether the following apply to the residential premises:

  1. signs of mould

  2. signs of dampness

  3. if there is a pests/vermin problem

  4. If there is loose-filled asbestos or rubbish is left on premises

Make sure you check out the checklist. It starts on Page 49.

Should I hire a building biologist to assess the rental home for mould?

One of the best decisions is to hire a building biologist.

Building biologists assess the condition of an entire home, rather than one room or area. They assess the entire home for mould and they determine the root cause.

Hire a building biologist for a mould & moisture assessment:

  • Pre-lease / pre-rental inspections – find out before you move in.

  • Post-rental inspections – You may not have noticed a problem until you moved in.

An experienced company such as Balanced Building Biology can assess your entire home for mould and they will provide an expert report on the current condition of the rental for you to consider.

If there is significant issues you can engage the landlord or real estate agent for action.

The Building Biologist’s Report

Once you get the mould report from the building biologist, you can show just the summary to the landlord to see what they propose doing about fixing the problem. If they still refuse to act, you may want to consider whether you should break the lease and move out of the property or take legal action.

Legal action may mean, taking your issue to the NSW Civil and Administrative Tribunal (NCAT). However, it is always best to try and resolve this with the real estate agent and/or the landlord.

The building biologist will need to be made aware ahead of time if you require a report for NCAT.

Fixing the Source of the Problem

When it comes to fixing a mould issue, focus on fixing the source of the problem, which is usually water leaks, humidity or condensation. Sometimes, a damp and wet subfloor / crawl space can be the culprit for your indoor air quality issues.

The real estate agent or landlord will need to address cause of the mould growth.

What if there is significant mould damage to my belongings?

The building biologist is not a mould remediator. Mould remediation needs to occur by a properly trained and IICRCcertified expert. The building biologist report should be used by the mould remediator to determine the scope of works and provide a quote for remediation.

This remediation quote may be the basis of a claim for loss or damage during the NCAT hearing, but ensure that the building biologist has sampled the potentially damaged items and had them laboratory-tested.

The Cost of Living with a Mouldy Home

If there is mould in your rented home and the landlord refuses to do anything about it, you might want to consider your options.

At this point, if you have been living in a mouldy home for a significant period of time, your health may be at risk and you definitely need to take action. This is usually the case for most of my clients. If you are looking for a new rental home, consider getting a pre-lease inspection before signing a rental agreement.