What Is a BASIX Certificate and When Is It Required?

If you're lodging a development application in NSW, you've likely come across the term BASIX certificate.

A BASIX certificate is a mandatory requirement for most residential developments under NSW planning legislation.

It’s a key component of the NSW planning system that ensures residential buildings meet sustainability targets.

BASIX stands for Building Sustainability Index and it’s managed by the NSW Government.

This requirement applies to all new homes, alterations and additions valued over $50,000, as well as swimming pools larger than 40,000 litres.

A planning consultant can guide you through the BASIX process to avoid delays in council approval.

What Is a BASIX Certificate?

A BASIX certificate shows your building design complies with NSW Government sustainability benchmarks.

It focuses on water efficiency, thermal comfort and energy use.

To generate the certificate, you'll need to complete a BASIX assessment using the online tool

This involves entering design specifications such as insulation, window glazing, lighting, heating and cooling systems.

As a town planning company, we incorporate BASIX requirements early in the design phase to streamline the development application process.

When Is a BASIX Certificate Required?

BASIX applies to a wide range of residential projects.

Here are the main scenarios:

New Homes

If you're building a new house, dual occupancy, townhouse or apartment block in NSW, a BASIX certificate is mandatory before you can obtain council approval.

We recently assisted a developer in Blacktown with a multi-dwelling application by ensuring all unit designs complied with BASIX targets.

Home Renovations Over $50,000

Major renovations or additions that exceed $50,000 in construction value will require BASIX compliance.

This includes projects like adding a second storey, large kitchen remodels or new living areas.

Our planning advice often includes a preliminary BASIX review to ensure smooth DA approval.

Swimming Pools Over 40,000 Litres

If your development includes a large pool or spa, a BASIX certificate is needed to manage its environmental impact.

We often recommend energy-efficient pumps and water-saving measures to meet these criteria.

Multi-Unit Developments

For apartment buildings and townhouses, each unit must meet BASIX standards individually.

We use integrated architectural drafting and planning support to ensure each dwelling complies from the outset.

CDC and DA Pathways

Even if your project qualifies for Complying Development under CDC, a BASIX certificate is still required in most residential cases.

It’s a common misconception that CDC exemptions apply to BASIX, but NSW planning rules treat sustainability as non-negotiable.

Why BASIX Matters for Your Development

Failing to submit a valid BASIX certificate with your development application can result in processing delays or outright rejection.

We’ve seen applicants miss council deadlines simply because BASIX was overlooked during early planning stages.

As planning consultants, we align BASIX documentation with design and drafting plans to keep your project compliant and moving forward.

How Town Planning Sydney Helps

Our team understands the technical requirements behind BASIX and its role in NSW planning policy.

We integrate sustainability benchmarks into every stage of the DA approval process.

By engaging us early, you reduce the risk of having to redraw plans or repeat assessments.

Our planning advice is grounded in practical experience across residential developments throughout NSW.

From granny flats in Penrith to duplexes in the Inner West, we’ve helped hundreds of homeowners and developers navigate council approval with confidence.