New build stage inspections
When and why to book independent stage inspections during new home construction: slab, frame, lock-up, fixing, and practical completion.
Why independent stage inspections matter
Building a new home or buying off-the-plan? Your builder has quality assurance processes, but an independent building inspector works for you — not the builder. Stage inspections catch defects and non-compliant work before it's covered up, when fixes are quick and inexpensive.
Common issues found during stage inspections include:
- Incorrect or missing structural bracing
- Poor waterproofing in wet areas
- Inadequate subfloor ventilation
- Incorrect flashing around windows and doors
- Termite barrier breaches
- Electrical and plumbing rough-in errors
These defects are expensive or impossible to fix after walls are sheeted and finishes applied. Catching them early protects your investment.
The 5 key construction stages to inspect
1. Base / slab stage
When: After the slab is poured and before framing begins.
What's checked:
- Slab thickness and reinforcement (steel mesh placement)
- Termite barriers (chemical or physical) installed correctly
- Damp-proof membrane placement
- Drainage and fall away from the slab
- Service penetrations (plumbing, electrical conduits)
2. Frame stage
When: After the frame is erected but before wall cladding or internal lining.
What's checked:
- Structural framing complies with plans and engineering specs
- Bracing (cyclone ties, hold-down straps) correctly installed
- Window and door frames square and level
- Roof frame structure and truss placement
- Wall and floor frame straightness and plumb
3. Lock-up stage
When: After windows, doors, and roof are installed, making the building weatherproof.
What's checked:
- Roof sarking and flashing installed correctly
- Window and door flashing to prevent water ingress
- External cladding and waterproofing
- Subfloor ventilation adequate
- Gutters and downpipes correctly installed
4. Fixing / pre-plaster stage
When: After rough-in plumbing and electrical but before internal walls are plastered.
What's checked:
- Waterproofing in wet areas (bathrooms, laundry, ensuite)
- Electrical rough-in complies with AS 3000
- Plumbing rough-in and fall on drains
- Insulation installed correctly (ceiling, walls, underfloor if applicable)
- Fire-rated systems in required areas
5. Practical completion / handover inspection
When: Before you take possession and the builder's defects liability period begins.
What's checked:
- All finishes are complete and to standard
- Fixtures and fittings correctly installed and functional
- Paintwork, tiling, and joinery quality
- Doors, windows, and locks operating correctly
- External works: driveways, paths, fencing, landscaping drainage
- Compliance with approved plans
This is your final chance to create a defects list for the builder to rectify during the defects liability period (usually 6 to 12 months in most states).
How many inspections do you need?
Most owners book 3 to 5 stage inspections:
- Minimum: Frame and practical completion
- Recommended: Base, frame, lock-up, and practical completion
- Comprehensive: All 5 stages including fixing/pre-plaster
If budget is limited, prioritise frame (when structural issues are still fixable) and practical completion (your defects list for the builder).
What if defects are found?
- Share the report with your builder immediately. Most defects can be fixed quickly at the right stage.
- Request rectification in writing. Document all defects and the builder's agreed fix timeline.
- Follow up with a re-inspection. Confirm defects are fixed before the next stage progresses.
- Escalate if necessary. If the builder refuses to fix defects, contact your state's building commission or tribunal (QBCC in QLD, NSW Fair Trading, VBA in VIC, etc.).
What about the builder's quality inspector?
Builders often have their own QA inspectors or certifiers, but they work for the builder — not you. An independent inspector:
- Has no commercial relationship with the builder
- Reports directly to you
- Checks against your contract and the Australian Standards, not just the builder's checklist
Costs
Stage inspection costs vary by property size and stage:
- Single-stage inspection: $350–$550
- Package (3 to 5 stages): $1,200–$2,500
Many inspectors offer discounted packages when you book multiple stages upfront.
Next steps
If you're building a new home, book your stage inspections early so the inspector can attend at the right construction milestones. Get quotes from building inspectors who specialise in new builds, or browse our inspector directory.