What’s the Difference Between a BIC and a DA?

If you’re planning work on your home or business in NSW, you’ve likely come across the terms BIC and DA.

Both involve dealing with council, both require detailed paperwork, and both can be confusing without the right planning advice.But they serve very different purposes.

As a leading town planning and architectural drafting company in NSW, we help clients every week who aren’t sure which one they need, or whether they need both.

Here’s a clear breakdown of the difference between a Building Information Certificate (BIC) and a Development Application (DA), and when you might need one or the other.

1. A BIC is About Safety and Legality of Existing Work

A Building Information Certificate confirms that existing building works meet legal and safety standards under the NSW planning system.

It’s commonly used when a structure has been built without prior council approval, or when you're buying or selling a property and want assurance that no enforcement action will be taken.

For example, if the previous owner enclosed a garage without council consent, you may need a BIC to avoid future compliance issues.

A BIC doesn’t approve new development, it just confirms what’s already there is acceptable to council.

2. A DA is About Approving New Development

A Development Application (DA) is required when you want to build something new, alter existing structures, or change the use of land.

This could include adding a second storey, building a granny flat, or converting a shop into a cafe.

A DA involves site analysis, design plans, and submission of detailed documents that align with NSW planning policies and your local council’s controls.

Getting DA approval can be complex, and working with an experienced planning consultant ensures your application is compliant, coordinated and realistic.

3. A BIC Can Be Used to Legalise Unapproved Works

If your home includes an unauthorised pergola or converted shed, a BIC allows you to regularise those works without tearing them down.

But councils may still require architectural plans and supporting documentation to assess safety and compliance.

In many cases, Town Planning Sydney helps prepare these plans in-house to speed up the process and reduce back-and-forth with council.

We recently helped a client in Bankstown secure a BIC for a patio built ten years ago without any approval, saving them time and stress during sale negotiations.

4. A DA Is Required Before Construction

Unlike a BIC, a DA is for proposed works, not retrospective ones.

You must get DA approval before starting construction, or you risk enforcement, fines or orders to demolish.

Town Planning Sydney regularly assists clients with end-to-end DA services, from architectural design through to final council approval.

We often work with homeowners building new homes, developers creating dual occupancies and business owners changing fit-outs in commercial spaces.

5. In Some Cases, You Might Need Both

Yes, it’s possible to need both a BIC and a DA on the same property.

For example, if part of your home was built without consent, you might apply for a BIC to legalise that section, and then lodge a DA to extend the property.

This often happens in older homes where previous owners made unauthorised changes and the new owner wants to renovate further.

An experienced planning consultant can advise you on the correct order of applications, so you don’t waste time or money.

6. Town Planning Sydney Simplifies the Entire Process

Dealing with NSW planning regulations, council approval, and compliance is complex.

Our team brings decades of experience across residential and commercial development applications, and we tailor our approach to your unique site.

We’ve assisted property owners in the Hills District, Inner West, Northern Beaches and beyond with BICs, DAs and everything in between.

By handling your architectural drafting and planning in-house, we reduce delays and ensure your application is council-ready from the start.

Need to understand whether you need a BIC, a DA or both?That’s where expert planning advice makes all the difference.