Unapproved building work in NSW: how a building information certificate works

In NSW, unapproved building work cannot be approved after the event through a development application. The only way to bring it into line is a building information certificate (BIC) issued by the council under Division 6.7 of the Environmental Planning and Assessment Act 1979. A BIC does not legalise the work. It stops the council from ordering the building to be repaired, demolished, altered or rebuilt, and from suing over an encroachment onto council land. For buyers, that protection is the point: a BIC before settlement means the enclosed carport, the converted garage or the rear granny flat is not going to become your compliance problem. A purchaser under a contract for sale can apply for one directly, but the council will only issue it if the work meets building standards and would have been approved had a DA been lodged.

Who this is for: home buyers and investors looking at a house in Sydney or regional NSW with extensions, enclosed verandahs, garage conversions or a granny flat that may not be approved, and sellers who want to clear the issue before marketing.

How do you know if building work is unapproved?

Start with the council’s records, not the agent’s assurances. The building work on a property should match a development consent or complying development certificate, a construction certificate and, for anything built since the late 1990s, an occupation certificate. Practical checks:

• Request the section 10.7 planning certificate and ask the council (or a certifier) for the approval history of the property.
• Compare the approved plans with what is on site. Extra rooms, a raised rear deck, an enclosed carport or a garage with a kitchen and bathroom are the usual mismatches.
• Look for an occupation certificate for the dwelling and any secondary dwelling. A granny flat with no occupation certificate is a red flag.
• Check the survey. Structures over a boundary or into an easement can create encroachment issues as well as approval issues.

The common mistake is relying on the contract’s disclosure. Vendors are required to attach certain documents, but the absence of an approval for the rear studio is often not obvious until a building inspector or a planner compares the site with the council file.

What does a building information certificate actually protect?

The NSW Department of Planning’s practice note on building information certificates explains the effect of section 6.25 of the EP&A Act. From the date of issue, the council cannot:

• make an order, or take proceedings for an order or injunction, under the EP&A Act or the Local Government Act 1993 requiring the building to be repaired, demolished, altered, added to or rebuilt; or
• take civil proceedings about an encroachment by the building onto land vested in or controlled by the council.

The protection applies indefinitely to unauthorised work carried out before the certificate was issued, but only for 7 years for matters arising solely from deterioration through fair wear and tear. A BIC can cover the whole building or just part of it.

What it does not do is just as important. The practice note is explicit that a BIC does not approve or legitimise the work. It does not stop a fire safety order or a rectification order under the Building Products (Safety) Act 2017. It does not stop proceedings under section 9.50 of the EP&A Act for carrying out development without consent. And it does not authorise a use. A garage converted into a habitable room may get a BIC for the building work, but using it as a separate dwelling is a separate question that needs its own approval.

Who can apply, and what will the council ask for?

Under Division 6.7, the applicants can be the owner, any other person with the owner’s consent, a purchaser under a contract for sale or the purchaser’s solicitor or agent, or a public authority that has notified the owner. Applications are made through the NSW Planning Portal. Councils can ask for building plans, specifications, survey reports and certificates, and in practice most will want:

Fees are set by each council in its fees and charges schedule under section 608 of the Local Government Act 1993. Because the application cannot be amended, missing or wrong information usually means a refusal and a new application, with a new fee.

How does the council decide whether to issue a BIC?

The council can issue the certificate if there is no matter, discoverable with reasonable care and skill, that would entitle it to order the building to be repaired, demolished or altered, or if there is such a matter but the council does not propose to act on it. The practice note says councils should consider whether the building meets relevant building standards and is structurally adequate, and, where there was never a consent, whether consent would have been granted had a DA been lodged. That “notional DA” is assessed against the section 4.15 matters and the current planning controls.

In planning terms, that means the work is tested as if it were proposed today. A rear deck that meets the DCP setbacks and privacy controls will usually get there with the right certificates. A granny flat built 400 millimetres off the boundary in a zone and location where the controls require more, or a second storey that pushes the house over the LEP height limit, is much harder. Where a reasonable consent authority would never have approved the notional DA, the practice note says a BIC is unlikely to be granted.

The process for a buyer, step by step

1. Before exchange, have a planner or certifier compare the council’s approval history with the building on site.
2. If unapproved work is found, get advice on whether it is likely to achieve a BIC, needs rectification first, or is unlikely to be certified at all.
3. Negotiate with the vendor: a BIC as a condition of the contract, a price adjustment, or a longer settlement so the purchaser can apply.
4. Commission the documents: survey, as-built drawings, engineering and trade certificates.
5. Lodge the BIC application on the Planning Portal, as purchaser if the contract allows.
6. Respond to any council request for information promptly. The practice note gives a deemed refusal period for a BIC of 40 days from lodgement or from when requested information is supplied.
7. If refused, read the reasons. The council must explain the work needed to allow a BIC to be issued, and section 8.25 of the EP&A Act gives a right of appeal to the Land and Environment Court. The Department’s practice note gives a 6 month appeal period; appeal provisions were amended in 2026 for some application types, so confirm the current time limit before relying on it.

Where buyers get caught

Buying first and dealing with it later is the expensive version. Once you own the property, you own the compliance risk, and councils can issue development control orders under Division 9.3 and Schedule 5 of the EP&A Act, including demolish works orders, as well as penalty notices. The second trap is assuming an older structure is safe because “it has been there for years”. There is no general time bar that makes unapproved work lawful. The third is the granny flat that is rented out. If the structure is not approved as a secondary dwelling, both the building and the use are at issue, and lenders and insurers may treat it differently too.

Definitions

Building information certificate (BIC)

A certificate issued by a council under Division 6.7 of the EP&A Act that prevents the council from ordering a building to be repaired, demolished, altered or rebuilt, or suing over an encroachment onto council land.

Unauthorised building work

Building work carried out without the development consent, complying development certificate or construction certificate it required, or not in accordance with them.

Notional DA

The council’s test of whether consent would have been granted had a DA been lodged for the work, assessed against current planning controls.

Development control order

An order under Division 9.3 and Schedule 5 of the EP&A Act, such as a stop work, demolish works or compliance order.

Occupation certificate

The certificate that authorises a new building, or a change of building use, to be occupied. A BIC can be issued for a building that has no occupation certificate.

Unapproved work is one of the checks we carry out in every development due diligence report, and where a granny flat or garage conversion is involved we advise on whether it can be regularised or should be replaced with an approved secondary dwelling. If you are about to exchange on a property with work you are unsure about, request a fee proposal for a quick pre-purchase review.