About

Building performance since 1993.

Architects who think in building science. Engineers who value design.

We design, certify and teach the Passivhaus standard. The proof so far: more than 4 million ft² of certified Passivhaus floor area, seven PHI-accredited certifiers on staff, and Ireland’s national Passive House guidelines, which we wrote.

Founded 1993 First certified Passivhaus in the English-speaking world Ireland, the UK and worldwide

The practice

How we got here.

Mosart was founded in 1993, at a time when energy efficiency in buildings was a marginal concern. Over the three decades since, the practice has moved from pioneer to principal: designing the first certified Passivhaus in the English-speaking world in 2004, and building the team, tools and methods that now underpin some of the most significant Passivhaus schemes in Ireland, the UK and beyond.

The role changes with the project. Mosart was Passive House designer for the 550 homes at Shanganagh Castle, is certifier for the 5,500 at Seven Mills, and was Passive House designer for Erne Campus. Developers, architects and contractors bring us in for the part they need.

The aim has not moved since 1993: buildings whose performance is measured, not asserted.

What we stand for.

Values

Excellence

Passivhaus is pass or fail. A building is modelled in PHPP, detailed junction by junction and tested with a blower door; it either meets the criteria or it is not certified. We like working to that kind of standard.

Sustainability

A certified Passivhaus may use at most 15 kWh/m² a year for space heating. Designing to that number, and then checking it in use, cuts more carbon than any statement of intent.

Collaboration

Certification is collaboration by definition: the buildings we certify are other teams’ designs. The work happens in shared PHPP files and junction details, not in a report at the end.

Resilience

Buildings outlast their design teams. We detail for moisture as carefully as for heat loss, and Pulse, our post-occupancy monitoring, goes back into finished buildings to check whether the assumptions held.

What we do

Four disciplines, one performance goal.

Architecture

Full architectural service and masterplanning from feasibility through to completion, with building physics embedded from day one. Passivhaus, ZEB and NZEB, designed and certified by the practice that helped set the standard in Ireland.

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Consulting

Passivhaus certification, energy modelling, thermal bridge analysis, airtightness strategy and post-occupancy evaluation. The largest independent team of Passivhaus certifiers in Ireland, working across every scale and climate.

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Learning

The Certified Passivhaus Designer course, the Certified Passivhaus Tradesperson programme, and bespoke CPD for practices, developers and local authorities. Trained more than 4,500 professionals across four continents.

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Pulse

Post-occupancy monitoring for Passivhaus buildings. Sensors installed, data interpreted, and evidence fed back into future designs. The loop between design intent and real-world performance.

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The numbers

1993Year founded. More than 30 years of low-energy design.

2004First certified Passivhaus in the English-speaking world. Designed and delivered by Mosart.

4,500+Professionals trained across four continents in Passivhaus design and construction.

4Mft²Certified Passivhaus floor area across residential, commercial and education.

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Leadership

Meet the team.

Tomas O’Leary

Founder and Managing Director, Passive House Certifier

Art McCormack

Founder and Director, Passive House Designer

Jill Noctor

Director

Stephen Donoghue

Director of Innovation and Growth, Passive House Designer

Mairead Healy

Financial Director

Dr. Eduardo Roque

Associate Director, Passive House Designer

Shane Kinsella

Associate Director, Passive House Certifier

Denis Manzke

Associate Director, Passivhaus Consultant

Behind them: a team of twenty-five, including seven PHI-accredited Passivhaus certifiers, the largest independent certification bench in Ireland.

Clients include

“We partnered with mosart for a large-scale residential development, and their ability to integrate sustainable solutions from design to completion was incredible. Their team is knowledgeable, approachable, and innovative.”

John McAllister, Architect

Next step

Work with us.

Tell us about your project. We will tell you what the Passivhaus standard requires and what it will take to get there.

Start a project → See our work →