Your development application is approved — congratulations. Now your conditions of consent say a structural engineer must prepare a pre-construction and post-construction dilapidation report before you can pull a Construction Certificate. Here is exactly what that means, why it protects you, and how to get it signed off by your certifier without delays.
If you have landed here after searching “dilapidation report NSW,” “who can do a dilapidation report,” or “pre-construction condition survey for my DA,” you are in the right place. JSBC Consulting is a Sydney-based structural and façade engineering consultancy and we prepare these reports as a routine part of our work. This guide explains the whole process so you can move from DA approval to a clean Construction Certificate with confidence.
A dilapidation report — also called a condition survey — is a dated, photographic and written record of the existing condition of the properties, structures and public infrastructure surrounding your site. It is taken twice:
The pre-construction report establishes an agreed baseline of pre-existing cracks, movement and damage. The post-construction report then compares against that baseline to determine, fairly and on evidence, whether your works caused any new damage.
Most owners and builders treat the dilapidation report as a box to tick for the certifier. It is far more than that. A properly prepared report:
The cost of a dilapidation report is small. The cost of a contested damage claim with no baseline evidence is not. This is risk insurance you can hold in your hand.
This is where many projects trip up. Conditions of consent in NSW almost always require the report to be prepared by a qualified structural engineering firm — not a builder, not a building inspector, not the owner. The consent will typically use the words “Engineer” or “Practising Structural Engineer.” If the report is not authored and signed off by a suitably qualified structural engineer, your certifier can reject it.
JSBC Consulting prepares qualified structural engineering dilapidation reports across Sydney, including the Burwood, Inner West and metropolitan council areas.
| Report | When | Why it matters |
|---|---|---|
| Pre-construction | BEFORE any demolition, bulk excavation or construction begins | This is a hold point. If you start works first, the baseline condition is lost and cannot be recreated. There is no second chance. |
| Post-construction | BEFORE the issue of any Occupation Certificate | Compares the post-works condition against the pre-construction baseline and states whether any damage was caused by the development. |
The single most important sentence in this article: the pre-construction dilapidation report must be completed and (in most cases) issued to the neighbouring owners before any works commence. Missing the pre-works survey cannot be fixed later. Once the excavator is on site, the original condition is gone.
This is the question that confuses almost everyone, and getting it wrong is a common reason certifiers send reports back.
You do not only survey the buildings immediately next door. Your conditions of consent require you to survey every property, structure and piece of public infrastructure that falls within the zone of influence of your excavation. The zone of influence is the area of ground around your excavation that could realistically be affected by the works.
The zone of influence is defined by the project geotechnical engineer in their geotechnical investigation report, and it is specific to your excavation depth and ground conditions. As a worked example, here is how it was defined for a real mixed-use development in Burwood, New South Wales:
The geotechnical report defined the zone of influence in these terms:
The “1 Vertical to 2 Horizontal” rule is a simple geometric projection. Starting at the base of your bulk excavation, you draw a line that rises one metre vertically for every two metres horizontally, projecting outward and upward toward the surface. Anything that sits above that line — any building, footing, buried service, footpath, kerb or roadway — is inside the zone of influence and must be surveyed.
The practical consequence: the deeper your excavation, the wider the zone of influence becomes. For every metre of excavation depth, the zone extends a further two metres horizontally beyond the base of the excavation at the surface.
A quick worked example:
So a deep basement on a tight site can pull neighbouring properties two or three lots away into the zone of influence. This is why you should never assume “just the immediate neighbours” — always check the geotechnical report’s definition against your excavation depth and measure the projection from the base of excavation.
Important: Always use the zone of influence defined in your project’s geotechnical report. The 1V:2H ratio above is the definition adopted for the Burwood example. Other sites may adopt a different ratio depending on soil type, rock head, groundwater etc, so the geotechnical engineer’s definition governs.
A frequently missed condition: where only part of a building falls within the zone of influence, the report must still cover the whole building. Do not survey only the portion near the works. Certifiers check this.
A thorough dilapidation report covers far more than the neighbour’s lounge-room wall. The scope typically includes:
Properties and assets
Condition detail for each element
Photographic standard
You cannot survey a building you cannot get into, and neighbours are not always cooperative. The conditions of consent anticipate this:
Handled this way, a refused access does not hold up your Construction Certificate — but an undocumented gap will.
There is a genuine tension here. An overly thin report gets rejected by the certifier and leaves you exposed in a dispute. An over-engineered report costs more than it needs to. The sweet spot is a report that:
A report that does these five things is both defensible and proportionate. It is the balance of quality versus cost that actually serves you: enough rigour to protect you legally and satisfy the certifier, without padding you do not need.
A compliant dilapidation report should include:
The post-construction report is not a fresh survey — it is a deliberate re-shoot of the same properties, elements and viewpoints captured before works, so a true before-and-after comparison can be made. It must explicitly state whether, by comparison with the pre-construction report, any structural damage has occurred to adjoining buildings, infrastructure or roads, and where damage is found, whether it resulted from the development works. It is issued before any Occupation Certificate and distributed per the consent.
| Do | Don’t |
|---|---|
| Complete and submit the pre-works report before any demolition or excavation — it is a hold point. | Don’t let any site works start before the pre-construction report is issued. |
| Date every survey and photo, and keep the numbering consistent. | Don’t rely on undated or unindexed photos. |
| Cover the whole of any building partly within the zone of influence. | Don’t limit the survey to only the portion near the works. |
| Distribute copies to all required parties and keep proof. | Don’t forget the certifier, Council, Planning Secretary or adjoining owners. |
| Document refused access in writing to the certifier. | Don’t simply omit a property with no explanation. |
If your conditions of consent require a pre-construction or post-construction dilapidation report, JSBC Consulting can prepare a structural engineering report that is mapped to your exact consent conditions, correctly applies your geotechnical zone of influence, and is built to satisfy your certifier first time — protecting you against future damage claims without unnecessary cost.
Get in touch to discuss your project and your conditions of consent.
This article is general guidance for developers, builders and owners in NSW. The conditions of your specific development consent and the definition of the zone of influence in your project’s geotechnical report always prevail. Always read your conditions in full.
