Building science, verified
What 'Certified' Actually Means
Plenty of builders say Passivhaus. Certification is the difference between a claim and a measurement.
A certified Passivhaus is modelled before construction, blower-door tested below0.6 air changes per hour, and audited by an independent certifier. A home "built to Passivhaus principles" carries none of those checks. The wordcertified is the only part of the promise that gets measured.
The test behind the word
Four things that are true of a certified Passivhaus — 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.
Five questions to ask any "Passivhaus" 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 theCertified Passive House teamand read the Bluebush case study — described by its owner as only the third certified Passivhaus in Tasmania.
Frequently asked questions
Certified vs principles — your questions answered
What is the difference between a certified Passivhaus and a home "built to Passivhaus principles"?+
A certified Passivhaus 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 Passivhaus?+
Yes — Bluebush Passivhaus, described by its owner as only the third certified Passivhaus in Tasmania. 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.
Accredited & proud member of
Let's build your Forever Home.
Book a no-obligation consultation with our team and start the journey.
Book a Consultation