Quick answer: Building defects are faulty or unsatisfactory building work. In new homes, the most common are cracking and slab movement, waterproofing failures, roof and gutter leaks, drainage and plumbing faults, electrical faults, and poor finishes. The law gives you time to have them fixed: in NSW, generally 6 years for major defects and 2 years for other defects; in Victoria, action can be taken up to 10 years after the work was completed. In Queensland, strict deadlines apply, some as short as 3 months. Report every defect to your builder in writing, keep copies, and act early.
Last updated 4 October 2026. Written by the REIN Editorial Team. Researched with the help of AI tools, then fact-checked against the sources below.
Reviewed by Scott Fraser, founder of REIN, licensed real estate agent (NSW) with 10 years on the developer side of house and land.
What Counts as a Building Defect?
The Queensland Building and Construction Commission (QBCC) describes defective work as faulty or unsatisfactory building work that can show up during or after construction. It includes work that doesn’t comply with the Building Code of Australia or the relevant Australian Standards.
Regulators split defects into two broad groups:
- Major or structural defects affect the structure, safety or weatherproofing of the home. The QBCC’s examples include a leaking roof and a loose handrail.
- Other or non-structural defects are mainly about finish and workmanship. The QBCC’s examples include roof tiles in the wrong colour and cracked floor tiles.
Not every imperfection is a defect. Queensland and Victoria both publish standards and tolerances guides that set out what is acceptable, such as how much cracking or unevenness is allowed and over what period. If you and your builder disagree, these guides are usually the starting point.
The Most Common Building Defects in New Homes
1. Cracking and slab or footing movement
Cracks in walls, ceilings or the slab can be cosmetic, or a sign of movement in the footings. Movement is more likely on reactive clay soils or where site preparation and drainage were poor. Wide, growing or stepped cracks need a structural opinion.
What to check: ask for the soil report and the engineer’s slab design before construction, and have your inspector check the slab before the frame goes up.
2. Waterproofing failures
Showers, bathrooms, laundries and balconies are the usual problem areas. Failed waterproofing often isn’t visible for months, then shows up as mould, swelling, lifting tiles or water staining in the next room.
What to check: ask who applied the waterproofing membrane, request photos before tiling, and ask for the waterproofing certificate at handover.
3. Roof, flashing and gutter leaks
Poorly fitted flashings, cracked or loose tiles, and badly graded gutters let water in, often only during heavy rain. Under the QBCC definition, work that allows water into a building is a structural defect.
What to check: have your inspector go into the roof space at the practical completion inspection, and check ceilings again after the first big storm.
4. Drainage and plumbing faults
Stormwater that ponds against the slab, downpipes not connected, incorrect pipe falls, and leaking joints are common. Poor site drainage can also contribute to slab movement over time.
What to check: walk the site after rain, confirm every downpipe is connected, and ask for the plumber’s compliance certificate.
5. Electrical faults
Typical issues include power points or lights that don’t work, missing or incorrect safety switches, and fittings not installed as per the plans.
What to check: test every switch and power point at handover, and ask for the electrician’s certificate of compliance.
6. Poor finishes and workmanship
Uneven tiles, poor paintwork, doors that don’t close properly, gaps in cabinetry and scratched benchtops are the most common items on handover defect lists. They are usually cheaper to fix, but they still need to be fixed.
What to check: go room by room with a checklist at the practical completion inspection, and photograph everything.
7. Ventilation, insulation and condensation
Missing or poorly fitted insulation, bathroom fans that don’t vent outside, and poor sub-floor or roof ventilation can lead to condensation and mould.
What to check: ask your inspector to confirm insulation is installed as specified, and check where exhaust fans actually vent.
How Long Does a Builder Have to Fix Defects?
Your rights come from state law, not just your contract. Consumer Affairs Victoria puts it simply: the implied warranties apply by law and can’t be signed away. The main time limits, as published by each state regulator, are:
| State | Key time limits |
|---|---|
| NSW | Generally 6 years to act on major defects and 2 years for other defects, from completion. If a defect appears in the last 6 months of the warranty period, you get an extra 6 months to start dispute resolution. |
| Queensland | Lodge non-structural defect complaints with the QBCC within 12 months of completion, and structural defects within 12 months of noticing them. To stay eligible for the Queensland Home Warranty Scheme, report structural defects within 3 months of noticing them, and non-structural defects that appear in the first 6 months within 7 months of completion. The QBCC can direct a builder to fix work for up to 6 years and 6 months after completion. |
| Victoria | Action on the implied warranties can be taken up to 10 years from completion. Domestic building insurance, which covers you if the builder dies, becomes insolvent or disappears, covers structural defects for 6 years and non-structural defects for 2 years. |
The Queensland deadlines are the ones that catch investors out. If you’re buying a house and land package in Queensland, put a reminder in your calendar for 3 and 6 months after handover, and inspect the property properly at both points.
What Is a Defects Liability Period?
Many building contracts include a defects liability period. It’s a set time after handover, often 12 months or more depending on the contract, during which the builder agrees to come back and fix defects you report.
A defects liability period doesn’t replace your statutory warranty rights. It sits alongside them. When it ends, you can still rely on the time limits in the table above. The practical value of the defects liability period is that it gives you a clear, agreed process for getting the builder back on site early.
In Queensland, the QBCC says builders must fix defects you notify within 12 months of the work being finished. Read your contract to see how your defects liability period works and how defects must be reported.
How to Get Building Defects Fixed
- Document it. Photograph and date every defect, and keep your contract, plans, inspection reports and all correspondence.
- Tell the builder in writing. The NSW Government says to let the builder know in writing and keep a copy. The QBCC asks owners to give written notice of every defective or unfinished item, with a timeframe for it to be fixed.
- Give reasonable access. In Queensland, the QBCC defines this as a time agreed with the builder during normal working hours, with at least 48 hours’ notice.
- Escalate to the regulator if it isn’t fixed. In NSW, contact NSW Fair Trading or the Building Commission NSW. In Queensland, lodge a defective work complaint with the QBCC, which can inspect the work and issue a direction to rectify. In Victoria, apply to Domestic Building Dispute Resolution Victoria through the Building and Plumbing Commission.
- Claim on home warranty insurance if the builder has died, become insolvent or disappeared. See what happens if your builder goes bust.
Don’t withhold progress payments or refuse handover without getting legal advice on your contract first. Doing it the wrong way can put you in breach.
How to Reduce the Risk of Defects Before They Happen
- Check the builder first. Look up their licence and complaint history with the state regulator, and read our house and land builder reviews.
- Use your own inspector at each stage. Book stage inspections at slab, frame, lock-up and fixing, by an inspector you engage, not the builder’s own supervisor.
- Don’t skip the practical completion inspection. Bring your own licensed inspector, and use our practical completion inspection checklist.
- Buying an established or recently finished home? Get a pre-purchase building inspection before you commit.
- Read the contract before you sign. Check the defects liability period, the inclusions and what’s excluded.
How REIN Fits In
REIN doesn’t inspect buildings or fix defects, and you should use a licensed building inspector at every stage of your build. What we do is check the house and land package before you sign. We’re a buyer-only house and land advocate: we review the package and contract, show you the builder commission inside the price, and rebate 100% (excluding GST) of it to you. A REIN service fee applies, and the rebate typically covers the fee and more.
Builder commissions can run into tens of thousands of dollars. Getting part of that back can make it easier to pay for proper stage inspections from slab to handover.
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Common Questions About Building Defects
What are the most common building defects in new homes?
Cracking and slab movement, waterproofing failures, roof and gutter leaks, drainage and plumbing faults, electrical faults, poor finishes, and insulation or ventilation problems.
How long does a builder have to fix defects in NSW?
In NSW you generally have 6 years to act on major defects and 2 years for other defects, from completion of the work. Tell the builder in writing as soon as you notice a problem.
How long does a builder have to fix defects in Queensland?
The QBCC can direct a builder to fix defective work for up to 6 years and 6 months after completion. But to stay eligible for home warranty cover, report structural defects within 3 months of noticing them. Non-structural defects that appear in the first 6 months must be reported within 7 months of completion.
How long does a builder have to fix defects in Victoria?
Consumer Affairs Victoria says action on the implied warranties can be taken up to 10 years from when the work was completed. Raise defects with the builder in writing first, then apply for dispute resolution if they aren’t fixed.
Is a defects liability period the same as a warranty?
No. A defects liability period is set by your contract and gives the builder an agreed window to fix defects after handover. Statutory warranties apply by law and last longer.
Can I claim for defects if my builder goes broke?
Usually through home warranty insurance, sometimes called home building compensation or domestic building insurance. It generally applies when the builder has died, become insolvent or disappeared. Check your certificate of insurance before construction starts.
Sources
- QBCC – What is defective work (accessed 4 October 2026)
- QBCC – Help with defective work (accessed 4 October 2026)
- QBCC – Standards and tolerances guide (accessed 4 October 2026)
- NSW Government – How to make sure your new building work remains trouble-free (accessed 4 October 2026)
- Consumer Affairs Victoria – Warranties and guarantees on building (accessed 4 October 2026)
- Consumer Affairs Victoria – Implied warranties and domestic building insurance (accessed 4 October 2026)
- Consumer Affairs Victoria – Building disputes, defects and delays (accessed 4 October 2026)
Disclaimer: This material is general information only and does not take your personal circumstances into account. It is not financial, legal, or tax advice. Time limits and rules can change and depend on your contract and circumstances. While we try to keep content accurate and current, we make no warranties as to accuracy or completeness and accept no liability for any loss arising from reliance, to the fullest extent permitted by law. You should seek your own independent professional advice.