BASIX & NatHERS Assessments
BASIX is the mandatory sustainability assessment for new dwellings, alterations and additions above a cost threshold, and pools above a volume threshold. NatHERS is the thermal performance modelling used to satisfy the thermal comfort component where the simplified method will not pass. Both are required at lodgement, and the commitments on the certificate become conditions of consent - which is why doing them early matters.
Free consultation
- BASIX 3–5 business days · NatHERS 5–7 business days
- BASIX from $450 + GST · NatHERS from $700 + GST
- Quoted fixed after a free scope check
The commitments are the point
People treat BASIX as a certificate to obtain. It is more usefully understood as a set of building commitments - specific glazing performance, insulation values, shading, fixture ratings and water systems - that become legally binding conditions of your consent.
That is why the sequence matters. Run as a design input, BASIX shapes decisions you were making anyway. Run at the end, it dictates them.
How it works
Applicability check
1 day
Whether BASIX applies, and whether NatHERS will be needed.
Assessment
3–7 business days
BASIX inputs prepared, or full NatHERS thermal model built.
Certificate issue
Same week
Certificate issued with the commitments listed for the drawing set.
What we take off your hands
What EHUP handles
- Determining whether BASIX applies to your project
- BASIX certificate preparation and lodgement documentation
- NatHERS thermal modelling where required
- Advising on the cheapest route to a pass before the design is fixed
- Reissue where the design changes
What you don't have to deal with
- A late certificate forcing a design change or a delayed lodgement
- Commitments on the certificate that are awkward or expensive to build
Frequently asked questions
Does BASIX apply to my project?
It applies to all new dwellings, to alterations and additions where the estimated cost exceeds the relevant threshold, and to swimming pools above a volume threshold. Thresholds are set in the regulation and change from time to time, so it is worth confirming rather than assuming - it is a two-minute check.
What is the difference between BASIX and NatHERS?
BASIX is the overall assessment covering water, energy and thermal comfort. Thermal comfort can be satisfied either by a simplified DIY method or by NatHERS thermal modelling. Projects with significant glazing, unusual orientation or open-plan design commonly need NatHERS because the simplified method will not pass.
Why do it early rather than at lodgement?
Because the commitments become conditions of consent, and they constrain glazing, insulation, shading and water fixtures. Running BASIX after the design is fixed either forces a redesign or produces commitments that are expensive to build. Running it as a design input costs the same and avoids both.
What if the design changes after the certificate is issued?
The certificate needs reissuing to match what is being built, and if it has already become a condition of consent, a modification may be required. Small design changes have a habit of breaking a BASIX pass, so tell us when the design moves.
Related services
Design Services
Drawings and technical design are where most applications either succeed or generate a request for further information.
Residential Council Approval
Most residential developments do not need a full Development Application.
Complying Development (CDC)
A Complying Development Certificate is the fast-track approval pathway.
Why clients choose EHUP
- 10+
- 250+
- 14
- 1
Not sure which approval you need?
Tell us the address and what you want to do. We'll help identify the appropriate planning pathway, whether it is exempt development, complying development or a full DA. Your first conversation is free.