The Next Generation of Homes: Cairn Goes All-In on Passive House

Today, 10th September 2025, marks a pivotal moment for the Irish housing industry as Cairn, a valued client of MosArt, officially releases its Position Paper on Passive House. This groundbreaking decision to adopt the Passive House standard for all future projects signals a major shift towards more sustainable, energy-efficient homes and sets a new benchmark for the construction sector in Ireland. At MosArt, we have been working tirelessly towards this moment for over three decades, and we are thrilled to see our expertise and advocacy for Passive House standards come to fruition on such a large scale.

What is Passive House?

Passive House is more than just a building standard—it’s a performance-based approach that ensures the highest levels of energy efficiency, comfort, and indoor air quality. The standard’s core principles include continuous insulation, airtight construction, high-performance windows, thermal bridge-free design, and heat recovery ventilation. These features collectively lead to a dramatic reduction in heating energy demand, cutting it by as much as 55%, while providing superior comfort, health benefits and long-term cost savings for residents.

According to Cairn’s Position Paper, projects such as Pipers Square and Cooper Square will set the precedent for future large-scale Passive House developments. With a combined 1,200 apartments planned for completion by 2025, these initiatives highlight the commercial viability of Passive House at scale.

For residents, the benefits are clear. Cairn’s projections estimate that homes built to Passive House standards will reduce annual energy bills by up to 41%, while providing healthier, quieter, and more comfortable living environments.

Leading by Example

This is not just about energy efficiency—it’s about leadership. Stephen O'Shea, from Cairn, noted during the event, “We’re hoping to lead by example and lead the industry in a direction that we think is important.” This sentiment resonates deeply with the sustainability movement in Ireland, as other developers will likely look to follow Cairn’s lead.

Caroline Ashe Brady, chairperson of the PHAI (Passive House Association of Ireland) added, “Now is Passive House's time,” reflecting the growing recognition that the future of housing must focus on more than short-term gains. The shift to Passive House offers long-term benefits for both the environment and the people who live in these homes.

Emma Osmundsen, an industry leader and pioneer in Passive House development, encapsulated the excitement: "We don't need estate agents. The occupants sell Passive Homes as the stories are just so compelling." The success of Passive House lies in the experience of those who live in these homes, making the case for this standard stronger than ever.

At MosArt, we’ve been championing Passive House for over 30 years. Our Managing Director, Tomás O’Leary, who attended today’s event, remarked, "With Cairn now embracing Passive House across all future developments, we’re on the brink of a transformative shift for the entire industry."

What Happens Next?

So, what’s next for the Irish construction industry? Cairn’s bold move is expected to have a ripple effect across the sector. Other developers will be prompted to adopt similar standards, not only to remain competitive but also to meet rising demand for sustainable, high-performance homes. With the Irish government pushing for carbon reduction in housing and consumers prioritising energy-efficient living, the Passive House standard is set to become the new norm.

The shift towards Passive House will undoubtedly increase the need for certified professionals who can design, manage, and execute these advanced projects. For those in the building industry, now is the perfect time to consider upskilling. Programmes such as the Certified Passive House Designer (CPHD) course offer invaluable expertise in delivering high-performance, sustainable buildings. With this growing demand, becoming certified will put professionals at the forefront of the industry’s future.

A New Era for Housing

Cairn’s Position Paper signals the start of a new era for housing in Ireland—one defined by sustainability, comfort, and long-term value. As Stephen O'Shea concluded, “It's the direction we feel is right for us, it's the direction we feel is right for everyone. So get on board.”

The question is not if the rest of the industry will follow Cairn’s lead—it’s when. The future of Irish housing is Passive House, and it’s time to get ready for the transformation.