Passivhaus Perspectives: Scaling up natural, high-performance buildings

The Passivhaus Trust is delighted to bring you a new Passivhaus Perspectives series – bringing you expert opinions on a whole host of Passivhaus topics. We kick off with Gold Sponsor of the UK + IRL Passivhaus Conference 2025, PHT Patron Ecological Building Systems.

Passivhaus Perspectives: Niall Crosson, Ecological Building Systems - August 2025

The momentum behind Passivhaus is shifting. At Ecological Building Systems, we’ve witnessed a clear evolution to a new phase of genuine market demand. This reflects a wider transformation within the built environment, as forward-thinking architects, developers, and contractors embrace high-performance, nature-based solutions to meet climate challenges head-on.

Niall Crosson, Technical Director, Ecological Building Systems

Passivhaus momentum in the UK & Ireland

The Passivhaus Trust now estimates that 1% of all new homes in the UK are certified to the Passivhaus standard - a remarkable achievement, but only the beginning. At Ecological Building Systems, we share the ambition of growing this to 10% within the next decade, and our own data shows scaling demand across both new build Passivhaus and EnerPHit (Passivhaus retrofit) projects.

This aligns with the UK + IRL Passivhaus Conference 2025 theme: “Passivhaus in a Changing Climate.” As temperatures rise and energy resilience becomes critical, the market is recognising that Passivhaus delivers:

Assured building performance through rigorous testing and verification.
Energy efficiency that reduces operational costs and carbon emissions.
Comfort and durability, even under extreme weather conditions.

Operating in both the UK and Ireland, we support projects with a ‘Fabric First’ approach that prioritises long-lasting, natural, high-performance solutions.

Walking the talk

My own home, a contemporary vernacular house in Co. Cavan, showcases the construction of a certified Passivhaus in a scenic part of Ireland. Drawing on years of experience this fabric-first approach, prioritises low-carbon insulation, airtightness, windtightness, and effective ventilation to ensure long-term energy efficiency and indoor comfort.

Image credit: Ecological Building Systems

The resilience of Passivhaus in a changing climate was evidenced last January. Storm Éowyn’s record-breaking 183 km/h winds wreaked a trail of destruction throughout Ireland, with nearly 800,000 homes, farms and businesses losing power. In the aftermath, any homes without open fires, stoves or ranges were left without heating. We were no exception, the power cut lasting for almost a week. With subzero temperatures at night, and peaks of 5°C to 6°C during the day, temperatures within the living spaces never dropped below 20°C. This is a testament to the reliability of Passivhaus without a performance gap, even in such extreme conditions.

With elemental U-values averaging 0.11 W/m²K, provided by the Passive EcoWall® system, a space heating demand of 12kWh/m²/yr and heat load of 10W/m² was achieved, optimising comfort and minimising energy use.

The Pro Clima intelligent airtightness system, professionally installed by Clioma House, ensured Passivhaus levels of airtightness.

The careful selection of lower embodied carbon insulation, such as Gutex Multitherm boards and Thermofibre blown woodfibre insulation, combined with a timber frame structure, not only optimised thermal continuity, but leads to an exceptionally low embodied carbon from cradle to grave of just 373.3 kgCO₂e/m², comfortably beating RIAI and RIBA 2030 climate challenge and LETI targets.

Hands-on training demonstrations

At EBS, our ethos is built on sharing knowledge and building skills. At the 2025 Conference, we will not only exhibit but also host practical workshops on a range of our products.

Image credit: Ecological Building Systems

Delegates will be able to see how these materials and systems work together, forming a robust, lower-carbon, breathable, and energy-efficient envelope, making them ideal for achieving the rigorous performance standards of a Passivhaus.

Cross Laminated Timber (CLT) section locally supplied by Glenfort Timber Engineering (NI), used to demonstrate airtightness and weathertightness strategies, with:

Pro Clima Visto, a transparent membrane providing airtightness and weather protection for intermediate floors in multi-storey timber buildings.
Pro Clima Solitex Adhero 3000, a self-adhesive, windtight vapour-permeable external breather membrane.
Gutex natural woodfibre insulation, increasingly specified in both new build and retrofit Passivhaus schemes.

Passive EcoWall^® - a system highlighting thermal bridge-free detailing and robust LCA data to deliver a lower carbon, breathable, energy-efficient envelope. For internal insulation, the configuration typically includes:

Gutex Thermoflex: a flexible wood fibre insulation placed between wall studs, offering excellent thermal and acoustic performance.
Finsa SuperPan VapourStop E-Z: a racking board that functions as an airtight vapour control layer and structural board for timber frame walls and ceilings.
Pro Clima Tescon Vana: a Passivhaus and EPD certified high-performance adhesive tape used to ensure airtightness and windtightness at junctions and penetrations.

Nature-based innovation: EcoCocon partnership

One of the most exciting developments at EBS this year is our partnership with EcoCocon, winner of the Exemplar Sustainable Buildings Awards 2025. The prefabricated straw wall panels are:

98% bio-based yet structurally robust.
Designed to achieve Passivhaus performance levels with ease.
A scalable, accessible solution for the future of low-carbon building.

As EcoCocon’s exclusive distributor and technical partner in the UK and Ireland, we are proud to make this pioneering system available to projects seeking both performance and sustainability.

Ecococon Staw Panel: Products Winner - Exemplar Sustainable Building Awards 2025

As a company operating in both Ireland and the UK, we are seeing unprecedented demand for lower carbon insulation and airtightness products to help meet Passivhaus requirements in both new build and retrofit. From certified Passivhaus homes in Scotland, to Passivhaus schools in London and my own contemporary vernacular Passivhaus in Cavan Ireland, our products, technical back-up and training are supporting projects and helping to deliver comfort and carbon savings at scale.

Niall Crosson, Technical Director at Ecological Building Systems

Driving change together - Passivhaus momentum in the UK & Ireland

With strong roots in both Ireland and the UK, EBS is delighted that the first joint UK + IRL Passivhaus Conference 2025 is coming to Belfast in October. This landmark event will spotlight the rapid progress being made across the island of Ireland, alongside key UK updates on policy and exemplar projects.

We welcome this collaborative platform, are delighted to work closely with the Passivhaus Trust and the Passive House Association of Ireland, and are proud to be the Gold Sponsor of this landmark co-hosted event.

The 2025 Belfast conference will welcome visitors from across Ireland, the UK, Europe, the USA and beyond. For us, it’s more than an exhibition - it’s an opportunity to demonstrate how innovative, natural materials combined with practical training can accelerate the transition to a healthier, low-carbon built environment.

We invite you to join us at our stand or attend our practical workshop on 8 October 2025 in Belfast. Together, we can scale Passivhaus from niche to mainstream, delivering buildings that are not only energy efficient and durable, but also climate resilient and utilising materials with minimal upfront carbon emissions.