The 10 most common defects found in Sydney new builds
7 min read | Build Compass team | buildcompass.com.au
Talking with homeowners, builders and consultants alike all across Greater Sydney, certain defects come up again and again. Some are minor cosmetic issues. Others are serious enough to require full demolition and rebuilding of the affected area. Here are the ten we see most frequently seen and what you need to know about each one.
1. Hollow tiles in wet areas
This is the defect we find way to often. Wall and floor tiles in showers, bathrooms and laundries that produce a hollow 'clunk' when tapped have failed to bond to the substrate. In wet areas, this is not just a cosmetic problem, unbonded tiles allow water to travel behind the tile surface and into the structure. Under AS 3958.1, tiles must be fully bonded, and hollow tiles are defective at handover under section 12.5 of the guides to standards and tolernaces.
2. Missing or failed silicone at shower junctions
Every internal corner in a shower floor to wall, wall to wall connection must have a continuous flexible silicone bead, not grout. Grout is rigid and cracks as the building moves. When silicone is absent or applied poorly, water penetrates at the joint and reaches the waterproofing membrane or the substrate beneath. This is one of the leading causes of long-term water damage in new homes. Required under AS 3740,AS 3958.1 NCC Volume 2 2022 and section 12.7 guides to standards and tolerances.
3. No waterproofing compliance certificate
Legally required for all wet areas in NSW. The waterproofing must be applied by a licensed waterproofer who issues a compliance certificate. We regularly find homes where no certificate was obtained, which means there's no documented evidence that the waterproofing was installed correctly. Without this certificate, verifying or making a warranty claim for any future leak becomes significantly more difficult. Futhermore certificates that reference the wrong NCC clauses are Australian standards are often seen it is critical that the products referenced and the Australian standards and the certifitcate are up to date for the time of the construction project.
4. Plasterboard cracks and nail pops
Visible cracks in plasterboard walls and ceilings at handover are defective under section 10.14 of the guides to standards and tolerances. The default finish standard is Level 4 (per AS/NZS 2589), which requires all joints taped with minimum two coats of jointing compound, free of tool marks. Nail pops where fasteners push through the surface are defective at handover or within 24 months (S.10.19). These are common and almost always fixable, but must be documented.
5. Slab and floor levelness issues
Under Section 2.8, concrete floors are defective if they deviate by more than 4mm in any 2m length, or more than 10mm in any room, within 24 months of handover. We regularly find areas of slab that fall outside these tolerances, often in garages and laundries where the pour was completed quickly. Levelness issues can affect floor finishes, drainage falls, and door operation.
6. Doors and windows that bind or jam
Every door and window should operate smoothly with even clearance gaps. Binding or jamming within three months of completion is defective under Section 9.7. The gap between a door leaf and its frame should be 2–5mm uniform all the way around (S9.4). Sticking doors are often dismissed as a minor issue, but they can indicate frame movement, out-of-plumb walls, or moisture problems.
7. Paint defects runs, holidays and roller marks
Paint defects visible from 1.5 metres under natural (non-glancing) light are defective under Section 13.2. The most common issues we see are paint runs, missed spots (called 'holidays'), inconsistent sheen levels, and visible roller texture under oblique lighting. Exterior acrylic coatings must last a minimum of 36 months without failing (S13.5 Table 13.05). Examine walls from an angle, issues that look fine head-on become obvious when you change your perspective.
8. Incomplete or incorrect site drainage
The ground around the building should drain away from the structure, not towards it. Under Section1.3, surface water drainage is defective if it doesn't comply with the National Construction Code NCC Volume 2 2022 at the time of writing Part 3.3. We regularly find stormwater pits blocked with construction debris, downpipes not connected to drainage systems, and ground levels that direct surface water toward the house foundations.
9. Grout joint inconsistencies and poor finish
Under Section 12.6, grout joints must be consistent in width, uniform in colour, and free of voids. Floor tile joints should not exceed 3mm (for pressed tiles) and wall tile joints should not exceed 1.5mm. Tile lippage (the height difference between adjacent tiles) must not exceed 2mm (S12.9). Inconsistent grouting is one of the most visible indicators of a rushed tiling job.
10. Missing or incorrect handover documentation
This isn't a building defect in the structural sense, but missing documents is one of the most common issues we encounter and one of the most important. The home should come with: the waterproofing compliance certificate, the electrical CCEW, the plumbing certificate, the Home Building Compensation cover certificate, and the Occupation Certificate. Without these, your ability to make warranty claims, sell the property, or dispute future issues is significantly weakened.
What to do if you find these defects
Document everything with photographs, numbered to match your defects list. Record defects specifically and precisely (describe location, dimension, and nature). Give your defects list to the builder in writing at the end of the inspection and ask for a signed acknowledgement of receipt.
If you're not confident conducting the inspection yourself, our PC inspection checklist covers all of these items (and many more) using a structured checklist referenced directly against the NSW Guide to Standards and Tolerances 2017 and NCC 2022 for your piece of mind. With our vast netwrok of industry trusted proffesionals we can alos put you in contact with some of the most thorough inspectors across sydney.
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