A certified Passivhaus at Blackmans Bay — one of the first in Tasmania to earn the international mark, and the reason a family will heat this home for a fraction of what their neighbours pay, for the life of the building.
The brief
The owners didn’t want a house that merely looked efficient — they wanted one that could prove it. That meant building to the international Passivhaus standard and having it independently certified, not just “built to Passive House principles.” It was a five-year journey from first conversation to certificate.
The challenge
Certification leaves nowhere to hide. Every junction, every window reveal, every service penetration has to be modelled in PHPP and then built exactly as modelled — because at the end, an accredited certifier measures the result against hard limits. The airtightness target alone (a blower-door result at or under 0.6 air changes per hour) is a number most Australian homes miss by an order of magnitude.
The build
Designed with Maxa Design and delivered by our team under site manager Adam Caldwell, the home is a continuous, thermal-bridge-free envelope of 644.8 m² wrapping a treated floor area of 177.3 m², ventilated by a heat-recovery (MVHR) system moving 185 m³/hr of filtered, tempered fresh air. Certification was carried out by Jason Quinn of Sustainable Engineering Ltd, a PHI-accredited certifier.
The result — certified, not claimed
The certificate speaks for itself:
- Airtightness: 0.5 ACH₅₀ — inside the ≤ 0.6 limit
- Heating demand: 10 kWh/m²·yr — against a ≤ 15 limit
- Cooling + dehumidification: 4 kWh/m²·yr — against a ≤ 15 limit
- Primary energy (PER): 48 kWh/m²·yr — against a ≤ 60 limit
That heating figure is the headline: this home needs roughly 80–90% less energy to stay warm than a typical Tasmanian build. See the full technical story on the Bluebush certified Passivhaus case study, understand what the mark actually means in what “certified Passivhaus” means, or put your own bills through the Passivhaus savings calculator.
