Insights

Building performance in practice.

Articles on Passivhaus, policy, retrofit, and the science of buildings that actually work. From the team that designs and certifies them.

Passivhaus

How Much Does Passive House Certification Cost?

There is no single price: certification fees depend on size, complexity, unit types and the state of your PHPP. The cost drivers and timeline, explained.

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Building science

PHPP vs DEAP and SAP: Prediction or Compliance?

PHPP predicts real energy use; DEAP and SAP demonstrate regulatory compliance. Why a building can pass and still underperform, and when you need both.

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Policy

Passive House Grants in Ireland: What Actually Applies

What SEAI grants cover in 2026, why none of it applies to new builds, and how an EnerPHit deep retrofit can draw the same supports as any upgrade.

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Passivhaus

7 Passivhaus Certification Pitfalls to Avoid

The seven mistakes that most often derail Passivhaus certification, when each one bites on a project, and the cheap moment to fix it.

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Building science

Form Factor: Why Building Shape Drives Heat Loss

The heat loss form factor compares envelope area to floor area. Why compact forms need less insulation, and why shape is free at feasibility stage.

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Retrofit

What Is EnerPHit? Passivhaus for Retrofit

EnerPHit is the Passive House Institute's certified retrofit standard: 25 kWh/m²a heating demand or a component route, built around moisture-safe design.

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Passivhaus

The Ice Box Challenge Arrives in Ireland, and Mosart Is Designing the Boxes

Mosart is designing the boxes for the Ice Box Challenge as it arrives in Ireland, demonstrating Passivhaus envelope performance in a public, hands-on format at Trinity College Dublin and the ZEB Summit 2026.

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Policy

What Ireland’s new A0 BER rating actually measures (and what it doesn’t)

From 24th May 2026, Ireland’s BER system moves to an eight-band scale with A0 as the new top tier for Zero Emission Buildings. This piece examines what the rating measures, where it falls short, and what it means for design teams.

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Passivhaus

What It Costs to Build a Passive House in Ireland

Irish benchmarks from the SCSI, UK research on the Passivhaus premium, the cost drivers that matter and why the gap closes on bigger schemes.

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Passivhaus

Why Councils Choose Passivhaus for Social Housing

Lower tenant bills, fewer voids and a verified asset: the public-sector case for certified Passivhaus, with evidence from Irish and UK schemes.

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Building science

Passive House Windows Explained

Why a Passivhaus window needs Uw of 0.80 W/m²K, how glazing, frame, spacer and installation psi add up, and how the right glass becomes a heat source.

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Building science

Do Passive Houses Overheat? The Honest Answer

Passivhaus caps overheating at 10% of hours above 25°C. Why summer comfort is a design risk in any insulated building, and what controls it.

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Passivhaus

When Passive House Went Mainstream in Ireland

Professor Wolfgang Feist opens three large-scale Passive House schemes in Dublin in a single day: Whitehaven, Pipers Square, and Cooper Square. Over 850 homes. A look at what the moment means for social housing and the Irish industry.

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Passivhaus

Passive House Certification, Step by Step

The full route from feasibility to PHI certificate: who does what, how long each review takes, the documents required and what certifiers reject.

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Passivhaus

Is a Passive House Worth It?

An honest cost-benefit of building a passive house: UK premium research, Irish energy prices, comfort evidence, and the cases where it does not pay.

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Building science

Thermal Bridges and Psi-Values Explained

What thermal bridges are, how psi-values are calculated to BS EN ISO 10211, why default assumptions wreck PHPP results and when you need 3D modelling.

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Building science

Airtightness: What 0.6 ACH Actually Means

0.6 air changes per hour at 50 Pa is the Passivhaus airtightness limit. What n50 measures, how it differs from q50, and how to build to it.

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Learning

How to Become a Certified Passive House Designer

What the CPHD course covers, what it costs, how the PHI exam works, and what the credential actually does for your career in Ireland and the UK.

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Passivhaus

What Is a Passive House?

What a passive house actually is: the five design principles, the certification criteria, the history since Darmstadt 1991 and the myths worth retiring.

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Building science

What Is MVHR and Do You Need One?

MVHR supplies fresh filtered air and recovers heat from the extract. How it works, the 75% efficiency rule, filters, commissioning and open windows.

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Passivhaus

Passive House vs NZEB: What's the Difference?

NZEB is a regulatory minimum shown by calculation. Passive House is a voluntary standard verified by testing and independent certification. Compared here.

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Building science

What Is PHPP? The Model Behind Every Passivhaus

PHPP is the Passive House Institute's energy model and the tool of record for certification. What it checks, why it predicts real use, when to start.

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Building science

What Is a U-Value? A Plain Guide for Designers

A U-value measures how fast heat flows through a building element, in W/m²K. Lower is better. Here is the maths, the targets, and why lambda matters.

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Policy

Awaab’s Law and What It Means for Social Housing

Awaab’s Law introduces legally binding timeframes for social landlords to investigate and remediate damp and mould hazards. This piece explains the legislation, what it requires, and what providers should do now.

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Passivhaus

Pipers Square and the Future of Zero-Emission Housing in Ireland

Pipers Square, 598 Passivhaus apartments in Charlestown, Dublin, demonstrates how zero-emission housing can be delivered at scale today, ahead of the EPBD’s 2028 and 2030 mandates. A look at the compliance and ESG case.

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Passivhaus

A Milestone for Passivhaus in Ireland as Whitehaven Officially Opens

Whitehaven, 255 social and cost-rental Passivhaus homes in Santry, Dublin, officially opens. Mosart reflects on delivering the project as Passivhaus Designer and installing 1,100 sensors for post-occupancy evaluation.

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Passivhaus

Niven Oaks, Santry: Passive House Delivered at Scale

Niven Oaks, 268 Passive House apartments in Santry by Cairn Homes, with Mosart as Passive House consultant. A look at delivering the standard across a large residential scheme, where early data suggests heating costs up to 40% lower than a typical new build.

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Passivhaus

Passive House Momentum Rises Across UK and Ireland

The UK and Ireland Passivhaus Conference in Belfast signals a turning point: 600+ delegates, government commitment, and major housebuilders scaling up. An overview of the pipeline, the policy drivers, and what it means for the standard’s future.

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Learning

How Henry McKinney Turned His Mosart Training into Real-World Impact

Henry McKinney completed Mosart’s Certified Passive House Designer course and applied the skills on the Moville Passive House, a finalist at the Irish Construction Excellence Awards 2025. His experience shows what the training delivers in practice.

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