Building science, verified
Passive House Certification
Plenty of builders say passive house. Certification is the difference between a claim and a measurement.
A certified Passive House is modelled before construction, blower-door tested below0.6 air changes per hour, and audited by an independent certifier. A home "built to Passive House principles" carries none of those checks. The wordcertified is the only part of the promise that gets measured.
National recognition · 2026
2026 HIA Australian GreenSmart Awards — National Winner
Our certified Passive House, Bluebush, was named HIA Australian GreenSmart Home of the Year 2026 — proof of what a measured, certified home can deliver.
The test behind the word
Four things that are true of a certified Passive House — and unverified in everything else
Designed in PHPP
The home is modelled in the Passive House Planning Package before it is built — predicted energy use, comfort and moisture behaviour, not rules of thumb.
Tested, not trusted
Airtightness is measured with a blower-door test and must come in below 0.6 air changes per hour — a pass/fail number no marketing copy can fudge.
Independently verified
A third-party certifier audits the design, the documentation and the as-built evidence. The builder does not mark their own homework.
Certified people, not just projects
The Passive House Institute certifies individual tradespeople and designers. Who holds the certificate matters as much as what the brochure says.
The numbers
Three limits. Miss one and there is no certificate.
Passive house certification is not a scorecard you can pass on average. A home has to meet all three targets, and the certifier checks each one against evidence rather than intent. Below each limit is what our certified home at Blackmans Bay actually achieved.
| Requirement | The limit | Bluebush achieved |
|---|---|---|
| Annual heating demand | ≤ 15 kWh/m²·yr | 10 kWh/m²·yr |
| Airtightness (blower door, 50 Pa) | ≤ 0.6 air changes/hour | 0.5 air changes/hour |
| Primary energy renewable (PER) | ≤ 60 kWh/m²·yr | 48 kWh/m²·yr |
Bluebush was designed with Maxa Design and independently certified by Jason Quinn of Sustainable Engineering Ltd. Read the full performance record, or see how the standard is delivered on site by our passive house building team.
The process
How passive house certification actually runs
1 · Modelled before it is built
The design is entered into PHPP — the Passive House Planning Package — which predicts energy demand, comfort and moisture behaviour from the home's real geometry, orientation, glazing and construction. If the model misses, the design changes. This happens before contract, not after.2 · Detailed to remove thermal bridges
Junctions, penetrations and structural connections are drawn so the insulation layer stays continuous and the airtight layer stays unbroken. Most of the certification effort lives here, in details nobody sees once the linings go on.3 · Built, with the airtight layer protected
Sequencing matters. The airtight membrane has to survive every trade that follows it, which means the site team has to understand why it is there. This is where a certified teamseparates from an interested one.4 · Blower-door tested
A fan pressurises and depressurises the house and measures the air leaking through the envelope. It is a pass/fail number. An interim test partway through the build lets problems be found while they are still reachable.5 · Ventilation commissioned
The heat-recovery system is balanced and its flow rates measured against the design, so every room gets the air the model assumed it would.6 · Independently audited and certified
The certifier reviews the modelling, the construction evidence, the test results and the commissioning data. If everything holds, the certificate is issued — against the home, by name, permanently.
Five questions to ask any "Passive House" builder
- Who on your team holds a current Passive House Institute certification — by name?
- Have you delivered a home that is certified, not "designed to the standard"?
- What blower-door result did your last project achieve?
- Will my home be modelled in PHPP before we sign a contract?
- If we pursue certification, who is the independent certifier?
Any certified team answers these in one breath. Ours does — meet the Certified Passive House teamand read the Bluebush case study — one of Tasmania's first certified Passive House homes, independently verified at 10 kWh/m²·yr.
Frequently asked questions
Certified vs principles — your questions answered
What is the difference between a certified Passive House and a home "built to Passive House principles"?+
A certified Passive House has been modelled in PHPP, built to the standard, blower-door tested below 0.6 air changes per hour, and independently audited by a third-party certifier. "Built to principles" means none of that has been verified — it may be an excellent home, but nothing has been measured or independently checked.
Does certification actually change the outcome?+
Certification changes the accountability. Because the airtightness test and the certifier's audit are pass/fail, every detail — insulation continuity, junctions, penetrations, ventilation commissioning — has to be executed properly, not approximately. The measured result is what you paid for.
Has Zanetto Builders actually delivered a certified Passive House?+
Yes — Bluebush, one of Tasmania's first certified Passive House homes, independently verified at 10 kWh/m²·yr. We are Tasmania's Passive House building experts. Our team includes certified Passive House tradespeople, and certification is a path we can take any project down.
Do I have to certify my home?+
No. Certification is your choice, and plenty of our clients build high-performance homes without pursuing the plaque. The difference with a certified-capable team is that the discipline — the detailing, the testing culture, the building science — is there either way.
What does a certified passive house have to achieve?+
Three limits, all of them: annual heating demand of 15 kWh/m²·yr or less, airtightness of 0.6 air changes per hour or better under a blower-door test at 50 pascals, and primary energy renewable demand of 60 kWh/m²·yr or less. A home that misses any one of them does not get certified, regardless of how well it is built otherwise.
Who issues passive house certification in Australia?+
Certification is issued through the Passive House Institute framework by accredited independent certifiers — not by the builder, the designer or an industry association. Our certified home at Blackmans Bay was certified by Jason Quinn of Sustainable Engineering Ltd. Ask any builder who certified their project; a real answer names a person.
How much does passive house certification add to a build?+
For our projects, certification adds roughly 15% over an equivalent custom home — and most of that is not the certification fee, it is the envelope, the glazing and the ventilation system that make the numbers achievable. We break the premium down honestly in our guide to what a certified Passive House costs in Tasmania.
When should I decide whether to certify?+
As early as possible, and ideally before design is finalised. Certification is a design-led outcome — the modelling shapes orientation, glazing and construction build-ups. Deciding to certify partway through construction is usually either impossible or expensive, because the airtight layer and the detailing had to be planned from the start.
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