What Is the Passivhaus Trust?
The Passivhaus Trust is the UK's official Passivhaus organisation, and it's the first place to look if you want to understand the standard or build to it. As Trust members, we think it's worth knowing who they are and what they do.
Here's a quick guide, including where to find them if you're starting your first Passivhaus project.
Who is the Passivhaus Trust?
The Passivhaus Trust is an independent, non-profit organisation that leads the adoption of Passivhaus in the UK. It was founded by the AECB in 2010 and is the official UK affiliate of the International Passive House Association (iPHA).
That link is useful for members too. When you join the Trust, you automatically become a member of iPHA, so you're connected to the wider Passivhaus community as well as the UK one.
What does the Trust do?
The Trust has three main objectives:
- Promote the Passivhaus standard to industry and government
- Help increase the delivery of certified Passivhaus projects
- Preserve the integrity of Passivhaus standards and methodology
In practice, that includes bringing the industry together. The UK Passivhaus Conference returns to London's Queen Elizabeth II Centre on 18 November 2026, with the theme of scaling affordable comfort and resilience. It's aimed at architects, contractors, suppliers, policymakers and practitioners, and a Passivhaus Masterclass takes place the day before.
The Trust also runs open days, site visits and a Passivhaus Learning Hub, so you can see projects first hand and build your knowledge.
Why does Passivhaus matter?
Passivhaus is about buildings that perform as designed. The Trust describes Passivhaus homes as healthy, comfortable and warm, with ultra low energy bills, and says post-monitoring data shows they have no performance gap.
Airtightness is a big part of that. Passivhaus requires 0.6 air changes per hour or less at 50 Pa, so small leaks at junctions and penetrations matter. It's one of the five Passivhaus principles, alongside insulation, high-performance glazing, thermal bridge-free design, and ventilation with heat recovery.
Where do our products fit?
Our liquid-applied membranes help project teams create a continuous airtight layer, including at the junctions where leaks tend to happen.
- Passive Purple is our airtight vapour control membrane. It's certified by the Passive House Institute as Class A airtight (phA), at 0.02 m³/h·m² at 50 Pa to EN 12114.
- Passive Purple External is our breathable, watertight façade membrane. It's certified by the Passive House Institute as a Class phB component.
You can see the evidence behind both on our Tested & Certified page.
Planning a Passivhaus project?
Start with the Passivhaus Trust for guidance on the standard. For help with the airtightness layer, call our technical team on 01223 208174 or send us your drawings.