How Do I Get Approval for Unauthorised Building Works in NSW?

If you've built a deck, garage, granny flat or made any structural changes without council approval, you're not alone.

Across NSW, unauthorised building works are more common than many property owners realise.

The good news is, it's possible to resolve these issues legally, if you act quickly and follow the correct NSW planning process.

Here’s how to get started.

1. Understand What Counts as Unauthorised Building Work

If a structure was built without a development application (DA approval) or complying development certificate (CDC), it’s considered unauthorised.

This includes common additions like pergolas, extensions, sheds and even internal reconfigurations.

Even if the structure looks harmless or blends into the property, it still needs formal council approval under NSW planning laws.

In some cases, older works may pre-date current planning controls, but they still need to be assessed properly.

2. Stop Work Immediately and Get Expert Planning Advice

If the building work is ongoing, stop immediately.

Carrying on with unauthorised construction can trigger council fines, notices or legal action.

The next step is to speak to a planning consultant who understands the NSW planning system and local council rules.

At Town Planning Sydney, we help homeowners and developers resolve unauthorised works efficiently by managing the process from assessment to council approval.

3. Apply for a Building Information Certificate (BIC)

In most cases, the solution is to apply for a Building Information Certificate.

This certificate tells the council you want to legalise an existing structure rather than demolish or remove it.

The council then inspects the site and, if satisfied, confirms no further action will be taken for up to 7 years.

This process is often the only path forward if you want to sell, lease or refinance the property.

It’s also a standard step before lodging a future development application on the same site.

4. Prepare Supporting Documents

A BIC application must include accurate architectural plans and compliance documentation.

This is where in-house drafting and design support becomes essential.

At Town Planning Sydney, our team provides the full package, measured site drawings, plan documentation, and planning advice tailored to your local council’s expectations.

For example, in a recent case in the Inner West Council area, we helped a client legalise an unapproved rear extension built in 2017.

By preparing a clear plan set and coordinating a structural report, we secured the BIC and prevented further action.

5. Anticipate Additional DA or CDC Requirements

Sometimes a BIC isn’t enough.

If the unauthorised works don’t comply with current planning controls, the council may require a retrospective development application.

This is where a planning consultant adds real value.

We assess whether the structure can meet zoning, setback and heritage rules, and whether a CDC pathway is possible.

Every case is different, so it’s crucial to get customised planning advice before submitting anything.

6. Engage With Council the Right Way

Approaching council with a clear, well-documented case makes a big difference.

Planning authorities are more willing to cooperate when it’s clear you're trying to fix the problem properly.

Town Planning Sydney has deep experience working with councils across NSW.

We know what each local government expects, how to avoid unnecessary delays, and how to manage complex development application issues.

7. Avoid Unauthorised Works in the Future

Finally, it’s worth noting that fixing unauthorised works is always more expensive and time-consuming than getting DA approval the first time.

For future projects, always engage a planning consultant early in the process.

With the right planning advice and architectural drafting support, you can save yourself stress and secure council approval upfront.