Case study · Certified Passivhaus
Bluebush
Only the third certified Passivhaus in Tasmania — in the owner's words, not ours.
Certified
Passivhaus — independently audited
Maxa Design
Architecture · built by Zanetto · certified by Sustainable Engineering (PHI-accredited)
3rd in Tasmania
per the owner's public review
From brief to certificate
How a certified home gets built
The brief
A family set on a genuinely certified Passivhaus — not principles, not "inspired by" — designed by Maxa Design for Tasmanian conditions.
The discipline
Certification makes every junction accountable: insulation continuity, airtight detailing, ventilation commissioning — all of it audited, none of it approximate. Budget was managed in the open, with product switches and design tweaks recommended where they protected the outcome.
The test
A certified Passivhaus must pass a blower-door test below 0.6 air changes per hour and survive an independent certifier’s audit of the as-built evidence.
The result
Certification achieved: a blower-door result of 0.5 air changes per hour against the 0.6 limit, heating demand of 10 kWh/m²·yr against the 15 allowed — and a family, in the owner's words, "finally living very comfortably" in only the third certified Passivhaus in Tasmania.
The certified results — measured, not marketed
0.5
Airtightness n₅₀ (blower-door tested) · criteria ≤ 0.6
10
Heating demand kWh/m²·yr · criteria ≤ 15
4
Cooling + dehumidification kWh/m²·yr · criteria ≤ 15
48
Renewable primary energy (PER) kWh/m²·yr · criteria ≤ 60
177.3 m²
Treated floor area (certifier-checked)
644.8 m²
Thermal envelope, detailed airtight
185 m³/hr
MVHR commissioned for certification
Certified Passive House Classic — certificate 53380_SENZ_PH_20260410_JEQ, issued 10 April 2026 by Jason Quinn, Sustainable Engineering Ltd, authorised by the Passive House Institute. Every figure above is from the certificate.
What does a home like this cost?
We don't publish our clients' build costs — ever. What we can tell you: a certified Passivhaus typically adds around 15% to our custom starting rate, and pays it back in running costs every year after. Flip the Passivhaus toggle on thecost guide's starting-budget calculator to see your number, then run thesavings calculatorto see the other side of the ledger.
The owner's verdict
"It has taken us over 5 years, but we are finally living very comfortably in only the third certified Passivhaus in Tasmania, beautifully crafted by Zanetto Builders. We could not be happier with the build quality, the finish and the overall build process.
Kyle was a pleasure to deal with throughout the process. He recommended product switches and design tweaks to meet our budget; he recommended a great broker to help with the financing; and he drove the success of the project. Our site manager, Adam Caldwell, has an amazing eye for detail and genuinely cares about getting the best outcome in each and every case."
— Corey, owner · Google review
See Bluebush, then run your own numbers
Browse the full photo and video gallery, understand whatcertified actually means, and see what the standard could save on your energy bills.
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