Blower Door Test Cost Australia — From $600 (2026 Prices & ACH50 Targets)
A blower door test costs $600–$1,200 for a standard Australian home and tells you exactly how leaky it is — measured in air changes per hour at 50 Pa (ACH50). Testers operate in Sydney, Melbourne, Brisbane, Perth and Adelaide. It's the single most important diagnostic for high-star NatHERS, Passive House, and any home where comfort and bills matter.
Air-tightness targets in Australia
| ACH50 | Building type | What it means |
|---|---|---|
| 15+ | Old uninsulated home | Very leaky — drafty, expensive to heat/cool |
| 10 | Typical pre-NCC 2022 build | Leaky — wind-driven losses noticeable |
| 5 | Good NCC 2022 7-star build | Practical sweet-spot for comfort + bills |
| 1–3 | High-performance 8–9 star | Very tight — usually needs mechanical ventilation |
| ≤ 0.6 | Certified Passive House | Ultra-tight — MVHR mandatory |
What it costs (2026)
- • Single-storey home: $600 – $1,200
- • Double-storey / large home: $1,200 – $2,500
- • Thermal imaging add-on: + $300 – $600
- • Smoke leak diagnostics: + $200 – $400
- • Pre-lining + final test combo: 10–15% discount
When to test
- • Pre-lining — after wraps, before plasterboard
- • Final compliance — after fit-out
- • Pre-purchase — diagnostic on existing homes
- • Pre-retrofit — prioritise sealing investments
- • Passive House — mandatory for certification
Pair air-tightness testing with your NatHERS assessment
Several of our NatHERS assessors also offer accredited blower door testing — bundle them for a full design + verification package.