Site inspections & PS4 construction review
Independent, on-site verification at key stages to confirm your build matches the approved design and standards.
A structural site inspection is an engineer's independent check of structural work at a critical stage: before the concrete pour, before the framing is lined, before anything is buried or covered. We carry out inspections across Auckland and New Zealand-wide, leave a written record on site after every visit, and issue the PS4 construction review your council needs for Code Compliance.
Which stages need a structural inspection?
- Foundation excavations: confirming bearing before footings are poured
- Reinforcing steel: placement, cover and laps checked against the drawings
- Structural framing, beams and connections before linings close them in
- Retaining wall construction and drainage before backfill
- Remedial and pre-purchase structural assessments
What is a PS4 in construction?
A PS4 (Producer Statement, Construction Review) is the formal statement from the design professional who reviewed the builder's work, confirming that the building work was carried out in accordance with the consented plans and the New Zealand Building Code. Council relies on it before issuing your Code Compliance Certificate whenever the consent called for engineering involvement in construction, such as foundations, steel placement, fill compaction or specifically designed structure.
A PS4 can only be issued for work the engineer actually observed, which is why booking inspections at the right stages matters: an engineer cannot review work that is already buried.
Who can issue a PS4?
The PS4 comes from the design professional engaged to observe construction. That can be the original designer, a peer reviewer, or an independent, suitably qualified person agreed with Council. Councils often make it a condition of consent that a Chartered Professional Engineer (CPEng) monitors the structural work and issues the PS4.
In Auckland, Council's producer statement policy sets out the detail. Producer statements are accepted at Council's discretion from authors on its Producer Statement Register. After every inspection the engineer must leave a site record describing what was inspected, the findings and any instructions given to the builder, so the council inspector can see it. The PS4 is then supplied as soon as practical after the work is complete, backed by those records.
PS1, PS2, PS3 and PS4 at a glance
| Statement | Issued by | What it confirms |
|---|---|---|
| PS1 Design | The design professional | The building work as designed and documented complies with the Building Code. |
| PS2 Design review | A design professional who reviewed someone else's design | The design they reviewed complies with the Building Code. |
| PS3 Construction | The contractor who did the work | Specialist work such as piling, waterproofing membranes or cladding systems was built to the consented plans. |
| PS4 Construction review | The design professional who reviewed the contractor's work | The building work was carried out in accordance with the consented plans and the Building Code. |
The design side is covered in more depth in our guide What is a PS1?
What does a site inspection cost?
A single inspection with a written report is priced by location and scope, quoted fixed when you book, with PS4 documentation priced within a monitoring package rather than per visit. For projects outside Auckland we quote travel transparently, and for construction monitoring across a whole build our construction monitoring service (CM2 and CM3) is usually the better-value structure.
Pre-pour concrete inspections
The most common inspection we do is the pre-pour: the last chance to check foundation and slab reinforcing before concrete makes it invisible forever. We check bar sizes and spacing against the drawings, cover to the steel (the concrete depth that protects it from corrosion), lap lengths, starter bars and hold-down fixings, penetrations and setdowns, and the footing dimensions and bearing. Anything out is fixed while the formwork is still open, and the pour goes ahead on time.
How an inspection visit works
Your builder (or you) books the inspection a day or two ahead, telling us the stage and what is being covered up. On site, the engineer checks the work against the consented drawings: dimensions, materials, reinforcing placement and cover, fixings and connections, drainage falls. Anything that does not match is identified immediately and a fix agreed, usually while everyone is still standing next to it. You receive a written report the same day recording what was inspected, what was found and what, if anything, must change before the stage proceeds.
What the written report gives you
Each report states the date, stage, drawings referenced, observations and outcome, which builds the evidence chain behind the final PS4. That paper trail matters beyond council: it is what a future buyer's lawyer, an insurer or a dispute resolver will ask for when questions arise years later. Owners who keep our inspection reports with their property records are consistently glad they did.
What if the work was covered before it was inspected?
It happens: the slab is poured or the linings go on before anyone calls the engineer. The engineer can only sign a PS4 for what they observed, so a missed hold point usually means opening up the work, testing, or collecting other evidence, and council decides what it will accept. It is always cheaper to book the inspection. If a hold point has already been missed, call us before anything else is covered and we will work out the most practical way forward.
Inspections anywhere in New Zealand
Most of our inspection work is in Auckland, but engineered builds happen everywhere, and regional projects from Waikato to Queenstown regularly need independent PS4 construction review. We support remote projects with planned inspection visits scheduled around your critical stages, so distance never becomes a compliance gap.
Common questions
The builder says council inspects anyway. Why add an engineer?
Can I book a one-off inspection?
How much notice do you need?
Can you inspect a problem in an existing house?
What is the difference between a PS3 and a PS4?
What does the engineer leave on site after an inspection?
Do I need a PS4 for my Code Compliance Certificate?
Beyond new builds: assessments of existing structures
Inspections are not only for construction. We assess existing houses and structures for buyers before purchase, for owners worried about cracking or movement, and for insurers and lawyers who need an engineer's written opinion. The output is the same discipline applied to an existing building: a clear report stating what we observed, what it means structurally, and what to do about it, with costs and urgency ranked honestly.
Independent eyes at the moments that matter
Structural problems are cheap to fix at inspection and expensive to fix at discovery. An hour of engineering eyes at the right stage is the best money on the whole build programme.
Ready to start your site inspections project?
Tell us about your project and we will get back to you with practical engineering advice and a free, no-obligation quote.