Published data puts a typical professional mould job in Sydney at somewhere between $1,128 and $3,450, averaging around $2,230. That average is close to useless on its own, because the same bathroom can be quoted at $800 by one company and $4,000 by another, and both of them think they are being reasonable.
Here is what the Sydney market charges, what separates a cheap quote from an expensive one, and how New South Wales law handles the question of who pays. On that last point, NSW renters are in a weaker position than Victoria or Queensland, and it is worth understanding why before you start a conversation with an agent.
What Sydney providers are quoting in 2026
| Size of the problem | What you will be quoted |
|---|---|
| Isolated patch, under 1 square metre, surface only | $200 to $1,500 |
| A bathroom, a full wall, or one room, 1 to 10 square metres | $800 to $5,000 |
| Typical Sydney domestic job, published range | $1,128 to $3,450 |
| Multiple rooms, subfloor or wall cavities, 10 square metres and up | $2,500 to $15,000+ |
| Inspection with a written report | $150 to $800 |
| Air sampling, per sample set | $250 to $300 |
Drawn from published Sydney and national pricing as at August 2026. Most of the industry quotes excluding GST, so check which you have been given.
Why two quotes for the same wall differ by thousands
Because they are usually quoting different work. One priced cleaning what you can see. The other priced finding out why it is there.
- Surface treatment versus remediation. Treating visible growth on a painted surface is a few hundred dollars of labour. Opening the wall, removing saturated plasterboard and insulation, drying the cavity and relining it is a different job with a trade component attached.
- Whether the moisture source is in scope. A quote that does not include finding the cause is a quote to repaint the symptom. It comes back, and you pay twice.
- Containment and filtration. Doing it properly costs time and money. Skipping it spreads spores into the rest of the property, which is how one room turns into four.
- Verification. Post-remediation air sampling to prove the area is clear is a separate line. Owners corporations, insurers and agents usually want it, and in a strata building you will almost certainly need it.
Ask both companies the same question. What is causing the moisture, and is fixing it included in this number? You will know very quickly which quote is real.
If you rent in NSW, the law is weaker than you might hope
Victoria has a rental standard that names mould directly. Queensland has one too. New South Wales does not.
Under section 52 of the Residential Tenancies Act 2010, a NSW landlord must provide premises that are “in a reasonable state of cleanliness and fit for the tenant to live in”, and the minimum standards require the property to be structurally sound and to have adequate ventilation. Those standards have to be maintained through the tenancy, not just at the start of it.
Mould is not mentioned anywhere in them. So a NSW mould claim has to be argued through one of three doors: the property is not fit to live in, it is not structurally sound, or ventilation is inadequate. All three are arguable. None is automatic.
Which puts more weight on evidence than in Victoria or Queensland. If mould in a Sydney rental is coming from a failed shower membrane, rising damp through sandstone footings, a roof leak or a blocked box gutter, that is a structural fault and a repair obligation. But somebody has to establish that in writing, because “there is mould” on its own is not a breach of anything in NSW.
That is exactly what an independent inspection report does. It records moisture readings, identifies the source, and separates a building fault from a ventilation habit. We report what we find regardless of who is paying us, which is the only way a report is worth anything to either side.
Why Sydney properties in particular
- Apartments and strata. Sydney has a very high proportion of unit stock, often with bathrooms that have no window and a shared exhaust that vents into a riser rather than outside. Moisture has nowhere to go.
- Rising damp in older terraces and sandstone. Inner-city and eastern suburbs housing frequently predates damp-proof coursing. Moisture wicks up through masonry and shows as mould at skirting height.
- Coastal humidity. Harbourside and beachside suburbs sit at high year-round humidity, and mould does not need a leak when the ambient air is already doing the work.
- Box gutters and internal drainage. Common in Sydney terraces and warehouse conversions, and a slow overflow shows up inside as a ceiling stain long before anyone finds the cause on the roof.
- East coast lows. Sustained heavy rain events drive water into walls that cope perfectly well with ordinary weather.
Before you accept a quote
- Ask what the moisture source is, and whether anyone measured it.
- Ask whether the inspection fee is credited against the job if you proceed. Some providers do, some do not.
- Ask whether containment is included and where the removed material goes.
- In strata, ask whether the report is written to a standard the owners corporation and its insurer will accept.
- Check for IICRC accreditation. It is the industry standard and it is easy to verify.
How we price it
We do not quote mould over the phone, because the number would be wrong and you would be arguing about it later. The inspection comes first and produces a written report covering moisture readings, affected materials and air quality. The quote follows from the report. If it turns out to be a small surface job you could do yourself, we will tell you that.
Insurance and strata work welcome, and we bill insurers directly where the policy allows. Call AllAces Cleaning & Restoration on 1800 00 1010, or read about mould removal in Sydney and mould inspection and testing.
Related reading: mould remediation cost across Australia, the same breakdown for Melbourne, mould in rental properties, and black mould in Sydney homes.