If you’ve discovered illegal building works in Victoria, such as a deck, carport, extension or pool built without a permit, the situation can usually be resolved, just not with a backdated permit. There is no retrospective building permit in Victoria in the sense of approving work after the fact: a building permit authorises work before it is carried out. What you can do is have the existing work assessed, fix anything that doesn’t comply (under a building permit for that new work where one is needed) and document the result.
This guide explains what counts as illegal building work, what council can do, the risks of leaving it and the practical steps to put it right. Acting early keeps more options open.
What counts as illegal building works in Victoria?
Unapproved or unresolved building work usually falls into one of these groups:
- No permit at all – work that needed a building permit but never had one, such as a verandah, deck, garage conversion or extension.
- Beyond the permit – work that doesn’t match the approved plans, like a bigger deck or an extra room.
- After the permit lapsed – the BPC confirms that if a permit lapses and building work continues, the work becomes illegal.
- Never signed off – a permit was issued, but inspections were missed and no certificate of final inspection or occupancy permit followed. Occupying a new building without an occupancy permit is illegal.
Many owners inherit the problem from a previous owner and only find out during a renovation, a sale or a council inspection.
Can you get a retrospective building permit in Victoria?
Not in the sense most people mean. A building permit approves building work before it happens, and the Building Act 1993 doesn’t provide for issuing one retrospectively for work that has already been carried out. You may see the term “retrospective permit” used online; in practice, the path to compliance works like this:
- A registered building surveyor assesses the existing work against the building regulations.
- Parts that can’t be checked from the surface are exposed and inspected, or inspected and certified by a structural engineer.
- Any work needed to make the structure compliant is carried out under a building permit for that work, with the usual inspections.
- The outcome is documented, and any council notice or order is resolved with the municipal building surveyor.
At JLN we call this our Certificate of Compliance pathway. We’re upfront that it is not a backdated building permit. Its purpose is to give you, your council and any future buyer independent, documented evidence of what was checked, what was fixed and how the work now stands against the regulations.
It’s worth being clear about what this does and doesn’t do. Resolving the work doesn’t change the fact that it was originally built without a permit, but it deals with the practical problem: the structure is checked, brought into line and properly documented.
If your problem is a lapsed permit rather than no permit, talk to the original building surveyor first. Where only compliance certificates are outstanding, the BPC notes a new permit may not be necessary.
What can council do about unpermitted work?
Carrying out building work without a required permit is an offence under the Building Act, with heavy penalties. Your council’s municipal building surveyor can:
- serve a building notice (section 106), asking you to show cause why you shouldn’t have to carry out work on the building, such as alterations or demolition
- make a building order (section 111) requiring that work to be done if your response doesn’t satisfy them
- take the matter further, including prosecution, particularly where notices or orders are ignored.
A building notice gives you the chance to respond before any order is made. Don’t ignore it: note the dates, get a building surveyor to assess the work, and get legal advice if you want to dispute the notice.
What are the risks of leaving it?
- Safety. Unpermitted work hasn’t been through mandatory inspections, so problems with footings, framing, balustrades, wet areas or pool barriers may be hidden.
- Insurance. The BPC notes that missing final documents may affect your insurance and suggests speaking with your insurer. Check your policy for exclusions relating to unapproved work.
- Selling. Consumer Affairs Victoria tells buyers to check the Section 32 statement and contact council to find out whether permits were obtained for renovations and extensions, and warns that illegal alterations may become the buyer’s responsibility once they sign. If a vendor statement contains incorrect or insufficient information, a buyer may be able to withdraw from the sale, so get your conveyancer’s advice on what to disclose.
- Owner-builder sales. If you did the work as an owner-builder and sell within 6 years and 6 months, you’ll need a defects inspection report and, for work over $20,000, home warranty cover – see our owner-builder guide.
- Higher costs later. Work that ends up behind new linings, paving or landscaping has to be opened up again before it can be inspected.
How to fix illegal building works: step by step
- Gather what you have. Plans, photos taken during construction, invoices, engineering, the builder’s details and any council letters. A property information request to council under regulation 51 ($55.10 in 2026–27) can confirm what building permit records council holds.
- Site assessment. A registered building surveyor inspects the work, compares it with the building regulations and explains what can be verified, what needs to be exposed and what needs fixing.
- Expose and inspect. Footing depths, framing connections, fixings and waterproofing often can’t be checked from the surface, so some linings, cladding or paving may need to come off.
- Engineer certification. A structural engineer may inspect and certify elements such as footings and framing, or design any upgrades.
- Planning check. If the work also needed a planning permit, that has to be addressed with council’s planning department.
- Rectification under a permit. Any work required to bring the structure into compliance is carried out under a building permit, with mandatory inspections.
- Final documentation. Once everything is verified and complete, the outcome is documented, the rectification permit is closed with a certificate of final inspection where applicable, and evidence goes to council to resolve any notice or order.
How JLN can help
Our building surveyors assess unapproved building works, identify exactly what’s needed and guide you through to certification, whether you’ve received a council notice, found unpermitted work before selling or bought a property with a problem you didn’t create. We’ll give you fast, practical advice and a clear scope before any work starts. Learn more about our illegal building works service.
Frequently asked questions
Is a retrospective building permit possible in Victoria?
Not as a backdated approval. The practical alternative is to have the existing work assessed, fix what’s needed under a building permit for that new work, and document compliance.
Can I sell a house with unpermitted work?
Yes, but it can complicate the sale. Buyers are advised to check permits for renovations and extensions, and an inaccurate vendor statement can let a buyer withdraw. Getting the work assessed, and ideally resolved, before you list puts you in a stronger position.
The previous owner did the work. Is it my problem?
Often, yes. Consumer Affairs Victoria warns buyers that illegal alterations may become their responsibility once they sign the contract. The good news is that an assessment will show exactly what’s involved in making the work compliant.
Can a building surveyor sign off work they didn’t see being built?
Only to the extent they can verify it. That’s why hidden elements may need to be exposed, tested or certified by an engineer. The BPC notes a building surveyor may require work to be exposed to confirm compliance, or refuse to approve what can’t be verified.
Will I have to demolish the structure?
Not necessarily. Many structures can be verified and upgraded. Removal may be needed if the work can’t be made compliant, or if a building order requires it.
How long does it take to fix illegal works?
It depends on how much needs exposing, engineering and rectification, and whether planning approval is involved. If you’ve received a building notice with a deadline, start straight away.
Found building work without a permit? Call JLN on 0422 234 951 or contact us, and we’ll assess the work and explain your options in plain English.
This article is general information current as of September 2026, not legal advice. Every project is different – ask us to confirm what applies to yours.