Deep retrofit, designed to perform.
Most of the buildings that will stand in 2050 are already built. We retrofit them, from protected structures to social housing, to warm, low-carbon, certified standards. We are Design Team Lead on three council Pathfinder programmes.
New build gets the attention, but most of the carbon is locked up in buildings that already exist, and retrofitting them is harder than starting from scratch. Existing fabric, occupied buildings, heritage constraints and tight budgets have to be solved together. It is the work we are set up for, and the work local authorities have appointed us to lead.
We lead council Pathfinder retrofit programmes.
Ireland’s Pathfinder programme asks public bodies to retrofit their own buildings as demonstrators under the Climate Action Plan. Public bodies carry an obligation to cut carbon and primary energy by 50 percent, reach a minimum BER of B, and set a route to zero emissions by 2050. We are Design Team Lead on three council Pathfinder programmes, Leitrim, Galway and Mayo, and on further retrofit appointments with councils across Ireland, including Cork, Offaly and Dún Laoghaire-Rathdown.
Three protected structures, one campus
Design Team Lead on the decarbonisation of Áras an Chontae, the IT Lodge and the Infirmary Building in Carrick-on-Shannon: internal natural insulation to stone, external insulation, triple glazing, airtightness, heat pumps, PV and controls, on buildings that cannot simply be wrapped.
3 protected structures · 50% carbon cut targeted See the projectTwo community centres, targets exceeded
Design Team Lead on the retrofit of the Knocknacarra and Ballinfoile community centres: cavity insulation, triple glazing, solar film, airtightness, heat pumps, ventilation, PV and controls. Both buildings beat their performance targets, and the communities got warmer, cheaper spaces fit for decades.
2 community centres · 50%+ reduction achieved See the projectCounty hall, leisure centre and swimming pool
Design Team Lead on the decarbonisation of Áras an Chontae in Castlebar, Westport Leisure Centre and Ballina Swimming Pool. Swimming pools are among the highest energy users a council owns, and their high hot-water and humidity loads make them some of the hardest retrofits of all.
3 civic buildings · 50% carbon cut targeted See the projectThe hard cases, done properly.
Heritage & protected structures
Stone walls, listed facades, sensitive interiors. We solve the building physics with internal natural insulation and hygrothermal analysis, so the fabric stays safe and the character stays intact.
Social & public housing
Warm, dry, affordable homes for the people who need them most, delivered while residents stay in place. Rochestown House was one of Ireland’s earliest certified Passivhaus social housing retrofits.
Civic & community buildings
Offices, community centres, leisure centres and public buildings where running cost and comfort matter for decades. Leisure centres are among the hardest and most energy-hungry of all, and we are retrofitting two right now. The Pathfinder community centres already cost far less to run and serve their communities better.
EnerPHit, where it fits
When a building can reach the certified Passivhaus retrofit standard, the same team carries it there. When it cannot, we design the deepest retrofit that does stack up. More on EnerPHit →
One team, survey to handover.
Survey & feasibility
Understand the existing fabric, condition and heritage constraints, model it in PHPP, and set realistic targets against the budget and the brief.
Design that respects the building
Insulation, airtightness, glazing, ventilation and services designed as one system, detailed to keep heritage fabric safe and the architecture intact.
Deliver and certify
Through construction with site inspections, to BER, NZEB or certified EnerPHit where that is the goal, by the team that designed it.
Prove it in use
Monitor the finished building with Pulse, so the saving and the comfort are evidenced, not assumed, and feed the next retrofit.
Deep retrofit, answered.
What is a Pathfinder retrofit programme?
Pathfinder is Ireland’s public-sector decarbonisation programme under the Climate Action Plan: local authorities and public bodies retrofit their own building stock as demonstrator projects, proving how deep retrofit can be delivered at scale and creating a route the rest of the public estate can follow. The targets are typically a 50 percent reduction in carbon emissions and primary energy, a minimum BER of B, and a clear pathway to zero emissions by 2050. Mosart is Design Team Lead on the Leitrim County Council, Galway City Council and Mayo County Council Pathfinder programmes.
Can you retrofit protected structures and heritage buildings?
Yes, and it is some of the work we are best known for. Protected and historically sensitive buildings cannot be wrapped in external insulation and triple glazing without care, so the building physics has to be solved differently: internal natural insulation to stone walls, hygrothermal analysis to keep the fabric safe from moisture, and detailing that respects the architecture. On the Leitrim Pathfinder we are retrofitting three protected structures, including Áras an Chontae, on one campus. Every one is designed from the inside out.
How is this different from your EnerPHit service?
They work together. This page is the architectural service: leading a retrofit from survey and feasibility through design, heritage approvals, delivery and handover. EnerPHit is the Passive House Institute certification standard a deep retrofit can be certified to. Not every building can or needs to reach full EnerPHit, and we will tell you honestly which standard fits. When certification is the goal, the same team carries it through. See our EnerPHit retrofit page for the standard itself.
Do you retrofit social housing?
Yes. Warm, dry, low-running-cost homes matter most for the people least able to absorb a performance gap, and occupied social stock carries duties around damp and mould that retrofit directly addresses. Rochestown House in Dún Laoghaire was one of Ireland’s earliest certified Passivhaus social housing retrofits, combining deep retrofit with new-build extensions while keeping the community in place. We have also delivered housing retrofits at volume for local authorities including Cork City and Offaly County Council. We can also monitor the result in use through Pulse, so a landlord can evidence the improvement.
What does a retrofit actually achieve?
On the Pathfinder programmes the brief is a 50 percent cut in carbon and primary energy and a minimum BER of B, and on the Galway community centres both buildings exceeded their targets. In practice that means continuous insulation, airtightness improvement, triple or upgraded glazing, heat pumps replacing fossil heating, mechanical ventilation with heat recovery, PV and proper controls, designed together rather than bolted on. The occupant gets a warmer, healthier, far cheaper building; the owner gets an asset fit for decades more use.
Will you lead the whole project or advise the team?
Either. On the Pathfinders we act as Design Team Lead, carrying the project from appraisal through design and delivery. On other schemes we provide the building-physics and Passivhaus expertise alongside another design team. We also certify retrofits designed by others. Whichever way the work comes, the retrofit is designed by people who do it every week.
Have a building worth keeping?
Heritage, social housing or a public estate, tell us what you have and we will tell you honestly what a retrofit can achieve.