Building Commission NSW reviewed the certification work behind 728 new homes. The findings are about certifiers, but the file they were looking at is the same file a builder reaches for when a defect claim lands five years later.

Building Commission NSW audited 427 registered certifiers and reviewed the paperwork behind 728 new Class 1a homes. Fewer than half of the critical stage inspection records it looked at were accompanied by any photographic evidence of what the certifier saw on the day.

The Commission assessed overall certifier performance in the Class 1 space as reasonable, with room for improvement in defined areas. One certifier out of the 427 was referred for further investigation.

The audit was directed at certifier practice, not at builders. But the documents it examined are the ones a builder relies on when a defect claim arrives years after handover. They record what was inspected, when, by whom, and with what result.

What the audit actually looked at

Between June and December 2024, investigators reviewed each audited certifier’s three most recent occupation certificates for new residential Class 1a developments. That means single dwellings, townhouses, dual occupancies, villas and secondary dwellings. Alongside each certificate they pulled the critical stage inspection records and the documents relied on, with particular attention to structural engineer certificates.

Source: Building Commission NSW, Building certification work audits, Class 1, section 1.3.1.1.

The audits were conducted in the second half of 2024. The report was first published in July 2026 and updated in August, so the findings describe practice as it stood two years ago rather than practice today.

What is a critical stage inspection?

DEFINITION: CRITICAL STAGE INSPECTION

A critical stage inspection, abbreviated to CSI, is an inspection a registered certifier must carry out at a specified point in the build to determine whether the work is consistent with the approved plans, complies with legislative requirements and satisfies the conditions of consent. The inspections required, and the way the result must be recorded, are prescribed in the Environmental Planning and Assessment (Development Certification and Fire Safety) Regulation 2021. The record is a statutory document, not a site diary note.

The audit found the recording of those inspections to be the weakest area across the whole review. Each finding changes what the record is worth to someone reading it later.

•   Records kept as a combined summary rather than an individual record for each inspection do not comply with the legislation. The summary format generally left out the inspection result, the name of the registered certifier, the development address, and any inspections found to be unsatisfactory.

•   Certifiers frequently did not use the defined term satisfactory when recording a result. Instead the audit saw passed, acceptable, ok to proceed, progressing per plans, and in some cases no result recorded at all.

•   Some records carried the signatures of two registered certifiers, which leaves anyone relying on the record unable to tell which certifier formed the opinion.

•   Records on multi dwelling sites often failed to identify which specific building, or which location within the building, had actually been inspected.

•   Fewer than half of inspection reports were accompanied by photographic evidence, despite the Practice Standard for Registered Certifiers recommending that a device capable of taking and recording photographs be used. Councils were considered more likely to take photographs than private certifiers.

Then there is the finding that does the most damage to the value of a file. Many records were marked satisfactory even though the same record noted considerable compliance issues that would have warranted an unsatisfactory result, with no evidence explaining why the certifier had not treated it that way.

A record marked satisfactory while noting noncompliance, as the report puts it, can misinform and mislead a person relying on that record. The person relying on it is often the builder.

Why a builder should care about a certifier audit

The report opens its discussion of the certifier role by clearing up misconceptions about it, and the corrections cut both ways.

Registered certifiers are public officials. They do not work for builders, contractors, developers or property owners, even the one paying the fee. They do not supervise or manage builders, contractors or building sites. And an occupation certificate does not certify that the conditions of a contract between a builder and an owner have been met.

So the certifier is not a second set of eyes working on the builder’s behalf. What the certifier produces, however, is a contemporaneous statutory record made by an independent public official stating that the work at a given stage was inspected and found satisfactory. There is very little else in a residential build that carries that combination.

That matters years later in a defect dispute, when the question becomes what the frame looked like before it was lined, or whether the waterproofing was there before the tiles went down. A record naming the address, the inspection type, the certifier, the result and carrying photographs answers that question. A summary sheet saying progressing per plans does not.

It is the same lesson the regulator has been putting in front of the industry through its site work. Its regional inspection programme produced the three item defect checklist from regional inspections earlier this year, and the common thread between that work and this audit is that a defect and the evidence of a defect are two different problems.

The engineer certificate problem

The second cluster of findings goes to documents builders procure rather than documents certifiers create.

Certifiers were consistently issuing occupation certificates relying on structural engineer certificates for reinforced concrete and structural steelwork. In most instances those certificates did not name the person who physically inspected each element, whether piers, footings or slabs, and did not record the date each inspection occurred. The certificates generally indicated that a person from the engineer’s office had inspected the works. All were endorsed by an engineer authorised to make the statement, with qualifications, address and signature.

That is a certificate that establishes an office attended. It does not establish who attended, or when.

Two related findings sit alongside it. No slab inspection certificate reviewed in the audit included a soil classification, and where the piers and slab inspection was carried out by the certifier alone there was no soil classification available to rely on at all. Separately, a council certifier accepted a structural engineering drawing carrying an assumed Class M soil classification. The audit notes that assumed is not a referenced term a certifier can rely on when considering the evidence of suitability requirements of the Building Code of Australia.

None of this reads as carelessness so much as capacity. Residential is one of the busiest sectors engineers and certifiers work in, and their fees have not kept pace with their costs. Thin documents tend to be a symptom of thin margins.

Regional piers and slabs

One finding in this section deserves separate treatment because it describes a structural difference between metropolitan and regional practice.

The audit found that in regional residential construction, piers and slabs are mostly not inspected by practising structural engineers at all. Those elements are subject only to the critical stage inspection carried out by the registered certifier. In the Sydney basin, for the most part, the owner receives a structural engineer certificate of adequacy for piers and slabs from the inspecting engineer.

The report goes further. In regional areas, post audit discussions with councils confirmed that the owner who appointed the principal certifier is generally unaware that an engineer will not inspect the piers and slab, and the report records that this decision appears to have been made by the builder with the concurrence of the certifier.

Whether or not an engineer inspection is required in a given case, that is a disclosure gap rather than a construction one. An owner who assumes an engineer has signed off on the footings, and later finds out otherwise, is an owner with a grievance regardless of how sound the slab is.

The audit also records a regional project where a Sydney based engineer inspected the steel component of a slab remotely, viewing it via a live streaming camera held by the certifier.

Do critical stage inspection requirements differ between states?

They do, and the report says so explicitly, which is the finding with the widest relevance outside New South Wales.

The audit observed inconsistency in inspection requirements between New South Wales and the bordering jurisdictions of Queensland, Victoria and the ACT, despite construction methods being similar across all of them. Specifically, the ACT, Victoria and Queensland do not require inspections to be undertaken for wet areas and stormwater. Councils on the border reported problems as a result, and certifiers told the audit team that it causes confusion for certifiers and builders from bordering states operating in New South Wales.

For a builder who works across a border, or who brings a supervisor across from another state, that is a concrete operational fact rather than a policy abstraction. Two of the inspection stages that trigger a hold in New South Wales simply do not exist next door.

Stormwater is also the inspection the audit identified as the most likely to be missed. Certifiers reported that plumbers find it difficult to set a time, because plumbing work is progressively installed and exposed only briefly. Stormwater inspection records also carried the fewest notations of observed defects of any inspection type.

Screw piers and pool barriers

Screw piers. Many certifiers do not treat the installation of screw piers as a critical stage inspection, on the reasoning that no hole is left open to inspect and no concrete is poured. In practice certifiers are obtaining certification from the installer confirming the piers reached the appropriate depth and founding material. Some noted that in certain engineering designs the tops of the piers are visible at slab inspection.

Pool barriers. Certifiers are not fully aware that a pool barrier inspection must be recorded as a separate inspection with its own result, rather than folded into the final inspection record.

What happens next

The Commission has said it will use the findings to inform future compliance programmes, refine its auditing approach and issue further practice advice and education to certifiers. It describes this as its first large scale audit since the formation of Building Commission NSW.

It also lands at a moment of structural change. Construction certificates are being replaced by building approvals under the new state framework, and the certification system is being consolidated. Findings about record keeping standards published now are likely to shape what the replacement regime expects.

One administrative finding points the same way. Most councils are not entering critical stage inspection records or the documents relied on to determine an occupation certificate into the NSW Planning Portal, and the audit team had to contact councils directly to obtain them. Private certifiers, largely using a common software provider, were more consistent. Where a record lives determines who can find it later.

What builders can take from this

The file that sits behind a finished house is thinner and less consistent than most people assume, and the builder is one of the parties carrying the consequence. That is the same exposure at the centre of the documentation habits that decide disputes, applied to a set of records the builder does not create but can request.

A builder cannot direct a certifier, and should not try. What a builder can do is keep an independent photographic record at every stage that would be covered by an inspection, ask for a copy of the inspection record rather than assuming it will be there when needed, and check that the engineer certificates being handed over actually name a person and a date. None of that changes the standards the build itself is measured against. It changes what can be proved about them.

THE GOOD BUILDER TAKE

The number worth remembering out of this audit is not 427 or 728. It is that fewer than half of the inspection records reviewed had a photograph attached.

Every builder already knows that a photo taken before a wall is closed is worth more than a memory of the wall. This audit says that the official record, the one made by an independent public official and kept on a statutory file, frequently does not contain one either.

That leaves a straightforward conclusion. If the evidence of a stage being inspected and found satisfactory matters to you, the only version of it you can rely on being complete is the one you keep yourself.

Frequently asked questions

Source: Building Commission NSW, Building certification work audits, Class 1, report on audits conducted June to December 2024, first published July 2026 with an updated version published August 2026. Legislative references in the report are to the Building and Development Certifiers Act 2018, the Building and Development Certifiers Regulation 2020 including the Code of Conduct at Schedule 5, the Environmental Planning and Assessment Act 1979, and the Environmental Planning and Assessment (Development Certification and Fire Safety) Regulation 2021.

Last updated: 3 September 2026. The audit covers the period June to December 2024.

General information only. This article describes the content of a published regulator report. It does not constitute legal, building or professional advice, and certification and inspection requirements differ between states and territories. Builders should obtain guidance specific to their own jurisdiction and project.

Author: TGB Editorial