Building Science

What Is Passivhaus — and Why Does It Matter for Your Home?

A plain-language guide to the world's most rigorous building standard. What it is, how it works in Tasmania's climate, and whether it's right for your build.

HomePassivhaus Guide

The Four Principles of Passivhaus

Passivhaus is not a single technology — it's the interaction of four principles working together. Remove any one of them and the system doesn't work.

Thermal Envelope

A continuous, unbroken layer of insulation surrounds the entire building — walls, floor, and roof. No thermal bridges. Heat stays in winter, stays out in summer.

Mechanical Ventilation with Heat Recovery (MVHR)

Fresh filtered air is continuously supplied while stale air is exhausted. 85–95% of the heat from outgoing air is recovered and used to pre-condition incoming air.

Airtightness

The building envelope is sealed to prevent uncontrolled air leakage. Tested with a blower door to 0.6 air changes per hour at 50 pascals — 10× tighter than a standard home.

High-Performance Windows

Triple-glazed windows with thermally broken frames are oriented for solar gain in winter and shaded in summer. Windows become part of the heating system, not a liability.

Davies's Passivhaus Credentials

Luke Davies holds dual certification from the Passive House Institute: Passivhaus Designer and Passivhaus Tradesperson. These are internationally recognised qualifications — less than 100 practitioners in Australia hold them.

Davies Construction has completed Passivhaus-certified and Passivhaus-informed projects across Tasmania's northwest coast. Our PHPP (Passive House Planning Package) modelling is done in-house — not outsourced to a consultant who has never visited the site.

We're members of the Australian Passive House Association (APHA) and contribute to the industry knowledge base through training and mentoring other builders through Future Builder Co.

Passivhaus Questions Answered

What is Passivhaus?+

Passivhaus (German for 'passive house') is an internationally certified building standard focused on energy efficiency and indoor comfort. A certified Passivhaus home uses 70–90% less energy for heating and cooling than a typical Australian home, while maintaining superior air quality and thermal comfort year-round.

Is Passivhaus worth it in Tasmania's climate?+

Yes — especially in Tasmania. The northwest coast has cold winters (Sheffield averages 3–7°C overnight in July) and warm summers. A Passivhaus home stays 20–22°C year-round with almost no active heating or cooling. The climate is actually ideal: the large temperature differential between inside and outside makes the heat recovery ventilation system highly effective.

How much does Passivhaus cost in Australia?+

Expect a 10–15% premium over a standard custom home of equivalent quality — roughly $500–$1,000 per m² additional. The premium comes from triple glazing, MVHR system, continuous insulation, and the airtightness detailing. This cost is typically recovered within 8–12 years through energy savings, and the indoor comfort benefit is immediate.

Is Davies Construction a certified Passivhaus builder?+

Yes. Luke Davies holds Passivhaus Designer and Passivhaus Tradesperson certifications through the Passive House Institute. Davies Construction is one of a small number of certified Passivhaus builders in Tasmania and across regional Australia.

Do I need full certification or can I build Passivhaus-informed?+

Full certification is not required to enjoy most of the benefits. 'Passivhaus-informed' design applies the core principles — high insulation, airtightness, MVHR, solar orientation — without the full certification process. This is a popular choice for clients who want 80% of the performance at 5% of the added cost. We guide you through the right choice for your brief and budget.

Build Healthier, More Efficient

Talk to one of Tasmania's only certified Passivhaus builders about what's possible for your project.