How much does a BASIX Certificate cost in 2026?
💸 Building Your Dream Home in NSW? Here's What the BASIX Certificate Will Cost You in 2026
So, you’re about to build a new home or tackle a big renovation in NSW. Congratulations! One of the first things you’ll hear about is the BASIX Certificate.
It can sound complicated, but think of BASIX (Building Sustainability Index) as your home’s environmental report card. It's mandatory and ensures your new build is efficient with water, energy, and keeps you comfortable without huge power bills.
The cost for your BASIX Certificate is made up of two main parts: the NSW Government Fee and the Professional Assessor Fee (that’s us!). Here’s a clear breakdown of what you can expect to pay in 2026.
Part 1: The NSW Government BASIX Fee
This is a mandatory fee charged by the NSW Department of Planning and Environment for the certificate itself. It varies depending on the size and type of your project:
(Note: A small NSW Planning Portal service fee, currently around $5, is included in the above costs.)
Part 2: The Professional Assessor Fees (NatHERS & BASIX Completion)
This is the fee for an expert (like R8 Star) to do the detailed technical work needed to prove your design meets the strict sustainability targets.
🌡️ The NatHERS Assessment (Required for New Homes)
The biggest and most important part of BASIX for new homes is proving your house will stay warm in winter and cool in summer without excessive energy use. This requires a NatHERS Assessment.
What is a NatHERS Certificate?
The Nationwide House Energy Rating Scheme (NatHERS) uses sophisticated software to create a digital model of your home (the insulation, windows, orientation, etc.). This model is run through a simulation to generate a Star Rating (currently a minimum of 7 stars is required for BASIX).
Thermal Modelling Fee (Our Professional Fee):
Starts from $350
Why does it vary? This fee is based on the complexity and size of your design. A large, multi-level custom home takes much longer to model accurately than a small, standard design.
NatHERS Certificate Lodgement Fee (Government Fee):
$40 plus GST per dwelling
This is an additional government fee for officially lodging the NatHERS rating.
Good News: This fee is NOT required for Alterations and Additions BASIX!
✍️ BASIX Completion Fee
Once the thermal modelling is complete, we use the results to finalise the other two sections of BASIX: Water (taps, toilets, rainwater tanks) and Energy (hot water system, lighting, appliances).
BASIX Completion Professional Fee: Starts from $120
This covers our time to enter all the specifications, ensure all three BASIX targets (Water, Energy, Thermal) are met, and finalise the certificate ready for your Development Application (DA) or Complying Development Certificate (CDC).
🔑 Key Takeaway for First-Time Customers
Your total BASIX cost is a quoted amount that combines all three components Government Fees (certificate charges) + NatHERS Model Fee + BASIX Completion Fee.
Our Value to You: It’s not just about getting the certificate. Our job as R8 Star assessors is to use the thermal modelling process to find the most cost-effective path to meet the 7-star requirement. This means we can often advise on simple changes to your plans that save you thousands in construction costs or lifetime energy bills!
Need a precise quote for your new home or renovation plans?
Would you like to send us your architectural plans for an obligation-free, fixed-price quote?