Building a new home in Perth should mean moving into something perfect — or at least close to it. The reality is different. At every practical completion inspection (PCI) we conduct, we find defects. Sometimes it's a handful of cosmetic items that the builder will fix in a day. Sometimes it's dozens of issues across waterproofing, drainage, brickwork, and finishes that would cost thousands to rectify after you've already signed off and moved in. This guide covers the most common new build defects we find in Perth, why they happen, and what a PCI inspection catches before it becomes your problem.
What Is a Practical Completion Inspection?
A PCI (also called a handover inspection or defect inspection) is an independent assessment of a newly built home before the buyer signs off on practical completion and takes possession. The builder is required to deliver the home in accordance with the approved plans, the Building Code of Australia, and the contract specifications. A PCI identifies any defects, incomplete work, or non-compliant construction so the buyer can require the builder to rectify these items before settlement or handover.
This is your one window of leverage. Once you sign off on practical completion and move in, the builder's obligation to fix defects becomes a warranty claim — which is slower, harder to enforce, and often contested.
The Most Common Defects We Find
1. Waterproofing Failures
This is the highest-risk defect category. Waterproofing membranes in bathrooms, ensuites, laundries, and balconies must be installed correctly to prevent water penetrating the structure. Common waterproofing defects we find include:
- Membrane not turned up behind wall tiles to the required height (150mm minimum)
- Membrane not lapped correctly at corners and junctions — creating gaps where water can track behind tiles
- Shower hob (step) not sealed correctly, allowing water to seep under the shower screen and into the adjacent room
- Balcony falls insufficient — water pools rather than draining away, increasing pressure on the membrane
- Missing or inadequate membrane at external door thresholds where balconies or patios meet internal floors
Waterproofing defects are invisible once tiles are installed. You won't know there's a problem until water starts appearing in the ceiling below — by which time the damage is extensive and the builder may argue it was caused by your use, not their installation.
2. Brickwork Defects
Perth's double-brick construction means brickwork quality directly affects structural performance. Common brickwork defects include:
- Mortar voids: Gaps in the mortar between bricks where the bricklayer has not filled the joint properly. These create weak points and potential water entry paths.
- Weep hole blockages: Weep holes at the base of walls and above lintels must be clear to allow moisture drainage from the cavity. Mortar droppings blocking weep holes are extremely common in new builds.
- Cavity mortar buildup: Mortar that has fallen into the cavity between the two brick leaves during construction can bridge the gap and create a path for moisture to track from the outer wall to the inner wall.
- Cracked bricks: Individual bricks cracked during construction or from improper handling.
- Brick alignment: Walls that are not plumb (vertical) or have visible bowing.
3. Roof and Ceiling Defects
- Tile alignment: Roof tiles not seated correctly, with gaps that allow wind-driven rain to penetrate.
- Ridge capping: Loose or poorly bedded ridge caps that will lift in Perth's strong afternoon sea breeze.
- Flashing defects: Lead or metal flashings at wall-to-roof junctions not dressed correctly, creating water entry points.
- Ceiling fixes: Plasterboard joins that are visible (ridging), nail pops where screws haven't been set properly, and uneven cornices.
- Insulation: Missing batts, displaced insulation from trades working in the roof space after installation, or insulation not covering the full ceiling area.
4. Drainage and Site Works
- Site grading: The finished ground level must fall away from the building on all sides to prevent water pooling against walls. Incorrect falls are one of the most common site defects — and one of the most consequential for long-term building health.
- Stormwater: Downpipes not connected to stormwater drains, or connected to drains that don't flow to the street. We find disconnected downpipes at a surprising frequency.
- Retaining walls: Missing or inadequate drainage behind retaining walls, creating hydrostatic pressure that will eventually push the wall over or force water into the building.
- Driveway crossover: Incomplete, damaged, or non-compliant crossovers that don't meet council specifications.
5. Internal Finishes
- Paint defects: Uneven coverage, runs, missed spots, and paint on surfaces it shouldn't be on (tiles, fixtures, glass). These are cosmetic but indicate the quality of care taken during the build.
- Tile work: Lippage (uneven tile edges), cracked tiles, hollow tiles (not fully adhered — detected by tapping), and poor grout lines.
- Cabinetry: Doors not aligned, drawers that don't close properly, missing soft-close dampers, and scratched or damaged surfaces.
- Door and window operation: Doors that stick, don't latch, or have gaps at the weatherstrip. Windows that don't lock or seal properly.
Where New Build Defects Are Most Common in Perth
Northern Growth Corridor
Suburbs like Alkimos, Yanchep, and Burns Beach have seen rapid development over the past decade. When builders are under pressure to deliver volume, quality control suffers. Large-scale estates with multiple builders working simultaneously can produce inconsistent construction standards from lot to lot.
North-East Corridor
Ellenbrook, Brabham, Dayton, and Aveley are among Perth's fastest-growing suburbs. The combination of reactive clay soils (in parts of the corridor) and high-volume construction creates specific risks around footing design, site preparation, and drainage.
South-East Growth Belt
Piara Waters, Harrisdale, and Byford continue to develop rapidly. The reactive clay soils in this corridor mean that site preparation and footing design are critical — defects in these areas compound over time as the clay reacts to moisture changes.
Why Independent Inspection Matters
Your builder's site supervisor conducts their own quality checks before handover. But the builder has a direct financial interest in calling practical completion as quickly as possible — because they're carrying financing costs on the build and have the next project waiting. An independent inspector has no relationship with the builder and no incentive to overlook defects. Our inspectors work to Australian Standards, not the builder's internal checklist.
It's common to find dozens of defects at a new home PCI — ranging from minor cosmetic items to significant compliance issues. Even experienced builders leave items unfinished. Our report documents every defect with photographs and references to the relevant standard, giving you a clear list to present to the builder for rectification before you sign off.
Book a PCI Inspection
If you're building a new home anywhere in Perth, don't sign off on practical completion without an independent inspection. Our PCI inspections start from $465 and typically take 2-3 hours on site. As a 5-star rated building and pest inspection team across Perth, we inspect new homes from Two Rocks to Mandurah — and we know what to look for with every major builder operating in Perth.
Call 0481 575 747 for a free quote or book online.
