Plain English
Why Passivhaus?
What the standard actually is, what it delivers in practice, and whether it makes sense for your project. No jargon, no greenwashing.
What the standard actually is, what it delivers in practice, and whether it makes sense for your project. No jargon, no greenwashing.
Passivhaus (or Passive House) is an evidence-based building performance standard — not a brand, not a style, and not just an aspiration. It was developed by the Passivhaus Institut in Germany in the early 1990s and is now the world's most rigorous and widely adopted energy performance standard for buildings.
A building that meets the Passivhaus standard uses roughly 75–90% less energy for heating and cooling than a standard UK new build. It's not a vague target — there are specific, measurable criteria that have to be demonstrated using the PHPP modelling tool before certification can be achieved.
The standard can be applied to residential, commercial, school, or retrofit projects. It's not just for self-builders, and it's not just for Scandinavia.
Walls, roof, and floor all insulated to a significantly higher standard than Building Regulations minimum.
All junctions and penetrations designed to eliminate or minimise heat loss through the structure itself.
Triple-glazed, well-specified windows and doors that retain heat and manage solar gain effectively.
A continuous airtight layer throughout the building envelope — tested and verified, not assumed.
MVHR (mechanical ventilation with heat recovery) provides fresh filtered air while recovering most of the heat that would otherwise be lost.
Stable internal temperatures with no cold spots, no draughts, and no overheating. The building does what it should regardless of what the weather is doing outside.
Continuous filtered fresh air via MVHR means lower CO₂ levels, less dust, fewer allergens, and a noticeably better internal environment.
75–90% reduction in heating and cooling demand compared to standard new builds. Not a theoretical saving — a real one, month after month.
The specification required to hit Passivhaus is also specification that protects the building from moisture, condensation, and deterioration over time.
Certification requires third-party verification. Passivhaus isn't a self-assessment — it's an independently confirmed standard.
Lower operational carbon as standard. Combined with embodied carbon assessment, Passivhaus is the strongest platform for genuinely low-carbon buildings.
These come up in almost every conversation. Here's the honest answer to each.
MYTH
The upfront cost premium is typically 5–15% on a well-designed project. Over any reasonable assessment period, the running cost savings more than offset this. The whole life cost case is strong — and as a QS, I can show the arithmetic.
MYTH
You can open any window you like. The MVHR handles ventilation, but it doesn't prevent you opening windows. It just means you don't have to.
MYTH
Passivhaus originated in Germany but is certified on every continent. The principles adapt to any climate — in warmer regions the energy loads shift from heating to cooling, but the rigour of the standard is the same.
MYTH
EnerPHit is the Passivhaus standard for retrofit. Achieving it is harder than new build, but it's achievable and increasingly in demand.
MYTH
PHPP is detailed and rigorous — it's meant to be. That's why a trained consultant handles it. For the project team, the outputs are clear and actionable.
MYTH
Any competent contractor can build to Passivhaus with the right design information, clear details, and good site management. It's about precision, not magic materials.
Passivhaus is not right for every project. Some buildings have constraints — budget, programme, planning, or geometry — that make full certification impractical. That's worth knowing early, not discovering late.
But Passivhaus principles — good fabric, airtightness, managed ventilation, thermal bridge-free construction — are worth pursuing in almost every project, even where full certification isn't the goal. Better buildings don't require a certificate.
If you're not sure whether Passivhaus is achievable or appropriate for your project, a short feasibility conversation is usually all it takes to find out.