Passivhaus at 35: Why efficiency has become a resilience issue

This year’s International Passivhaus Conference in Essen brought together hundreds of designers, researchers, manufacturers and policy leaders from across the globe under the theme: Driving Transformation with Energy Efficiency.

For the Passivhaus Trust team, the event was not only a chance to learn from world-leading projects and research, but also a reminder of the extraordinary global community that continues to drive better buildings forward. It was also a pleasure to help shape the content of this year’s conference through Co-Director Sarah Lewis’s involvement on the Scientific Advisory Board.

From catching up with friends and collaborators old and new, to celebrating 30 years of the Passive House Institute and 35 years since the world’s first Passivhaus building, the conference felt both reflective and forward-looking. The movement has come a long way, and this year more than ever, it felt clear that Passivhaus is no longer a niche approach. It is rapidly becoming essential infrastructure for resilient communities.

Energy efficiency is now a resilience issue

Across presentations and discussions, one question kept resurfacing: can we afford not to build Passivhaus? As energy prices continue to rise and concerns around grid pressures and fuel security intensify, reducing demand is increasingly being recognised not only as a carbon issue, but as a resilience issue too.

Passivhaus offers proven protection against volatile energy costs while creating healthier, safer and more comfortable buildings for occupants. Poor quality housing has social and political consequences, particularly where residents are exposed to overheating, unaffordable heating costs and unhealthy indoor conditions.

The conference reinforced that building performance is no longer a “nice to have”, it is fundamental to delivering stable, future-ready communities.

Retrofit is no longer optional, it is a necessity.

Retrofit emerged once again, as one of the conference’s defining themes. Speakers repeatedly highlighted that we already have robust, tested solutions through the EnerPHit standard, and that failing to deliver deep retrofit now represents a major missed opportunity.

As pressure on global resources and energy systems grows, the need to reduce operational demand becomes increasingly urgent, regardless of how “green” our future energy supply may become.

The message was clear: the cleanest building materials are often the ones already in use.

Discussions around demolition versus retrofit were particularly striking, with speakers arguing that retaining and upgrading existing buildings must become central to climate strategy. Determination, technical knowledge and collaboration are enabling increasingly ambitious retrofit projects around the world, including challenging heritage and civic buildings.

Sarah Lewis, Co-Director of the Passivhaus Trust, reflected:

“Planetary health check 2025 is not looking great, but solutions are available and being discussed here at the conference. Passivhaus is part of the solution, but we need to do more with less and lean into what makes for meaningful human life beyond consumerism.”

Passivhaus has matured globally

This year’s conference also demonstrated just how far the Passivhaus movement has evolved. Projects presented ranged from schools and housing to cultural institutions, leisure centres and civic buildings across Europe, North America, South America and Asia. Again and again, speakers showed how strong building physics can support better outcomes across energy use, comfort, operational resilience and design quality.

Ann-Marie Fallon, Co-Director of the Passivhaus Trust, described the event as:

“An intense event full of critical technical information about not only how Passivhaus is delivered across the globe, but also how leadership and innovation are creating more resilient communities as a result...

I come away further energised and galvanised about Passivhaus as a way to deliver better communities and places, alongside really interesting technical dives on technology and research outcomes.”

A particular highlight for the UK delegation was the focus on education and leisure projects, including valuable lessons learned from UK Passivhaus leisure centres.

The presentation on Cranleigh Leisure Centre by PHT member Gale & Snowden and GT3 Architects demonstrated how lessons from Eclipse Leisure Centre had informed improvements to form factor and services distribution, creating an even stronger operational and financial case for Passivhaus leisure facilities. In some scenarios, projected operational savings reached into the millions.

The conference also celebrated the live certification of the Schwarzman Centre for the Humanities on stage, another milestone moment showcasing the growing prominence of Passivhaus within major cultural projects.

Technical innovation was another major focus, particularly around heat pump development, controls and building performance evaluation. Sessions highlighted how high-performing building fabric combined with well-designed systems can deliver exceptional outcomes, including heat pump COPs exceeding 6 in some monitored projects.

Comfort before carbon

Alongside the technical sessions, an important communication challenge emerged. As an industry, we often explain Passivhaus through engineering language, calculations and performance metrics. But the conference reinforced that to scale adoption further, we need to talk more about the human experience of buildings.

Comfort. Quietness. Health. Stability. Security.

These are the outcomes people understand instinctively, and this people-first narrative feels increasingly important as Passivhaus expands into mainstream delivery across larger and more complex building types.

At the same time, we must continue challenging the misconception that Passivhaus restricts creativity or acts as a barrier to good architecture. Instead, many speakers demonstrated how strong building physics can enable better, more ambitious design outcomes. Speaking about a firehouse retrofit project in New York, architect Michael Ingui said:

A global community with shared purpose

Perhaps most importantly, the conference reminded us of the value of collaboration. The international Passivhaus community remains remarkably open, generous and connected. Whether through research sharing, technical discussion or conversations between sessions, the event reinforced how much progress is driven by collective learning.

The conversations in Essen made one thing very clear: the solutions already exist. The challenge now is accelerating delivery at scale.

That’s why the UK Passivhaus Conference 2026 will focus on scaling affordable comfort and resilience. Join us this November as we explore how we can apply these lessons more rapidly, from retrofitting existing buildings to delivering resilient new communities and protecting people from rising energy and climate pressures.

Early bird tickets are now on sale and we hope to see you there.