DA vs CDC: How BASIX and NatHERS Fit Each Approval Pathway

Whether you lodge a DA or a CDC, BASIX and NatHERS still apply. Here is how the documents fit each pathway in NSW.
Every new home in NSW takes one of two approval routes: a Development Application, or DA, assessed by council, or a Complying Development Certificate, or CDC, issued by a certifier. The pathway changes who approves your project, but it does not remove the need for BASIX and NatHERS. Here is how they fit.
The two pathways in brief
| DA | CDC | |
|---|---|---|
| Assessed by | Local council | Private or council certifier |
| Best for | Projects needing merit assessment | Straightforward projects meeting set rules |
| Typical timing | Longer | Faster when criteria are met |
| BASIX required | Yes | Yes |
Where BASIX sits
A BASIX Certificate is required for both pathways. On a DA it forms part of the documents council assesses. On a CDC the certifier checks the design against the BASIX commitments. Either way, the certificate has to be prepared, lodged and reflected on the plans.
Where NatHERS sits
The NatHERS assessment is the most reliable way to satisfy the thermal comfort target inside BASIX, regardless of pathway. It produces the star rating and the certificate that underpin the thermal side of your BASIX.
Choosing your pathway
- If your project fits the Complying Development rules, CDC is usually faster.
- If your site or design needs discretion or varies from the standards, a DA may be required.
- In both cases, prepare BASIX and NatHERS together so the documents are ready when you lodge.
Frequently asked questions
Does CDC skip BASIX? No. CDC is faster but still requires a valid BASIX Certificate.
Can I switch pathways later? Sometimes, but it is best decided early as it affects documentation.
Not sure which pathway suits your build? Talk to us and we will prepare the right compliance documents.
BASIX & NatHERS specialists, a division of Contrive Consultants. We help NSW homeowners and builders achieve energy-efficient, compliant homes.