BASIX certificates for NSW homes
BASIX certificates for new homes, renovations, extensions and pools across NSW. Send your plans and we’ll confirm the assessment scope, required documents and fixed fee.
- Suitable for
- New dwellings · alterations over $50,000 · pools of 40,000 L or more
- From (ex GST)
- $300 pools · $400 alterations · $750 new homes with NatHERS
- Includes
- BASIX certificate, commitments schedule, Planning Portal fee
- Turnaround
- 1–2 business days for alterations and pools · 2–3 for new homes
Turnaround is confirmed in your quote and starts once all required information is received.
What you receive
- BASIX certificate generated on the NSW Planning Portal, ready to upload with your DA or CDC
- NatHERS certificate and stamped plans where the simulation method is used
- A schedule of commitments for the drawings, so the certifier sees the same insulation, glazing and fixtures that were assessed
- Practical design options, with the updates required to the documentation, if the design needs changes to pass
What to send
- Site plan with north point
- Floor plans for all levels, dimensioned, with room names
- Elevations and sections, showing ceiling heights, eaves and window heads
- Window and door schedule, if you have one
- Construction type: brick veneer, lightweight clad, slab or suspended floor
- Services: hot water, heating and cooling, rainwater tank, solar PV
- For alterations and additions, the estimated cost of the works. For pools, the volume.
Missing something? Send what you have and we’ll tell you what else is needed before quoting.
How it works
- Send your plans. We confirm the assessment scope, the required documents and a fixed fee, usually within one business day.
- Assessment. Water, energy and thermal performance are assessed from the drawings against the targets for your location and dwelling type.
- Options if needed. If the design falls short, we explain the practical design options and the updates required to the documentation. You choose, and we re-run the assessment.
- Certificate issued. The BASIX certificate, and the NatHERS certificate and stamped plans where used, are sent to you ready to lodge.
Frequently asked questions
Do I need a BASIX certificate for a renovation?
Yes, if the estimated cost of the work is $50,000 or more. Pools and spas with a combined volume of 40,000 litres or more also need one. Below those thresholds, BASIX doesn't apply.
How long does a BASIX certificate take?
Alterations, additions and pools are usually 1–2 business days. New dwellings with a NatHERS simulation are usually 2–3 business days from complete plans. If the design needs changes to pass, allow time to review the options. Turnaround is confirmed in your quote and starts once all required information is received.
Can I do BASIX myself?
The Planning Portal has a DIY thermal method for simpler designs, and you can complete the water and energy sections yourself. Most new homes use the simulation method because it gives more design freedom, and that needs an accredited NatHERS assessor.
What happens if my design fails BASIX?
We explain the practical design options that would get it over the line, such as insulation, glazing, shading or orientation changes, and the updates required to the drawings. You choose, and we re-run the assessment.
Do I need a new certificate if I change the plans?
If the change affects anything BASIX assessed, such as window sizes, floor area, insulation or services, the certificate has to be revised so it matches the plans. Minor revisions start at $120 + GST.
Is the Planning Portal fee included?
Yes. Our prices include the Planning Portal's BASIX certificate fee and, where a NatHERS simulation is used, the NatHERS certificate fee. Prices shown are ex GST.
About BASIX
BASIX (the Building Sustainability Index) is the NSW Government’s sustainability standard for housing. A development application or complying development certificate for a home can’t be lodged without one.
When you need BASIX
- New dwellings: houses, granny flats (secondary dwellings), dual occupancies, townhouses and apartments.
- Alterations and additions with an estimated cost of $50,000 or more.
- Swimming pools and spas of 40,000 litres or more, including a pool added to an existing home.
The certificate is lodged with your DA or CDC. The same commitments then carry through to the construction certificate and are checked before the occupation certificate is issued. A multi-dwelling development, such as a dual occupancy or townhouses, is covered by one BASIX certificate that lists every dwelling; a granny flat added to an existing home is assessed as its own dwelling.
What gets assessed
| Section | What it looks at | Typical commitments |
|---|---|---|
| Water | Potable water use against a target for your location | Fixture star ratings, rainwater tank size and connections, landscape and pool |
| Energy | Greenhouse emissions from running the home | Hot water system, heating and cooling, lighting, cooktop and oven, solar PV |
| Thermal performance | How much heating and cooling the building fabric needs | Insulation R-values, glazing type and size, shading, floor and roof construction |
New dwellings also report a materials index, which measures the embodied emissions of the main construction materials.
The standards since October 2023
BASIX standards increased on 1 October 2023. Thermal performance moved from an average of 5.5–6 stars to about 7 NatHERS stars, with separate caps on heating and cooling loads. Energy targets were tightened to cut emissions a further 7–11%, depending on location and dwelling type.
Designs that passed easily a few years ago can now fail on glazing alone. Seven design choices that make BASIX harder to pass covers the usual problems.
DIY or simulation?
The thermal section can be done two ways. The DIY method applies fixed rules for insulation and glazing and suits simpler designs. The simulation method uses an accredited NatHERS model of the whole dwelling. It takes more work, but it credits good orientation, shading and layout, so it usually needs fewer upgrades.
We use simulation for new dwellings and check whether the DIY method is the simpler route for alterations. More on NatHERS ratings →
Send your plans for a fixed quote.
We confirm the assessment scope, required information and fee before work begins. Turnaround is confirmed in your quote and starts once all required information is received.