Blower door testing — on its own, or as part of As-Built Verification
Airtightness is one pillar of checking that a home was built to its modelled NatHERS and Whole of Home specification. We test to AS/NZS ISO 9972 as ATTMA accredited tester #13381 — standalone, or inside the Verified package.
Airtightness within As-Built Verification
As-Built Verification (Verified package) checks glazing, insulation, Whole of Home services and airtightness against the modelled specification. The blower door test measures ACH50 so leaks can be found and fixed — and so a non-regulatory re-rate in HERO can use the measured result instead of the default assumption.
Illustrative example only. The result depends on the design and the test. Blower door testing is also available on its own if you only need airtightness.
Placeholder photoHow the airtightness check fits
Blower door test
Pressurise and depressurise to measure ACH50 — ATTMA accredited tester #13381, to AS/NZS ISO 9972:2015.
Find the leaks
Thermal imaging and smoke testing show where air is getting in, so they can be fixed before handover.
Alongside the wider check
In the Verified package, glazing, insulation and Whole of Home services are checked against the modelled specification at the same visit.
Report & certificate
Findings report and the non-regulatory Geokal Energy Efficiency Certificate of Compliance (Verified package).
Verify before handover
Builders sign off energy items, glazing and sealing to the surveyor, but are not required to test or verify them. Not verifying is a risk for both builder and owner. As-Built Verification — including the blower door test — finds issues while you are still on site.
Builder packages →Know it was built right
Your home is your biggest investment. A blower door test — or full As-Built Verification — tells you how the finished home compares with what was modelled, before you move in.
Talk to us →Just need airtightness testing or a draught investigation? Our specialist brand Building Airtightness handles standalone blower door testing and airtightness investigation.
buildingairtightness.com.au ↗Blower door questions
What is ACH50?
Air changes per hour at 50 pascals — the standard blower door measure of how leaky or airtight a building envelope is.
When should the test be done?
Near completion, once the envelope is sealed, so any leaks found can still be fixed before handover. We agree timing when we quote.
Will a test always improve my rating?
Not always. If the home tests tighter than the default assumption the rating may improve; if it is leakier, the test shows where to fix it.
Should I contact Geokal or Building Airtightness?
If you want NatHERS ratings plus As-Built Verification (or a measured-ACH re-rate), start with Geokal. For standalone airtightness testing or draught investigation, visit buildingairtightness.com.au — or ask us and we’ll point you to the right path.