Passivhaus Trust EnerPHit project database
An open database of certified Passivhaus and EnerPHit retrofit projects across the UK, each with monitored or modelled performance figures.
Source
Summarised from Passivhaus Trust, a Tier 2 source on Your Home Climate. We did not run this project; the figures below are reported by them. Click through to verify any of them at the original publication.
https://www.passivhaustrust.org.uk/projects/The problem
Most retrofit advice is generic. Homeowners and designers wanting evidence of what a deep fabric-first retrofit actually achieves in a UK climate need real, comparable projects, not glossy brochures.
What they did
The Passivhaus Trust hosts a searchable database of certified projects. EnerPHit is the certification for retrofits, applying tighter rules than new-build Passivhaus because original geometry constrains what is possible. Each entry typically records space-heating demand, airtightness (n50), heating system and ventilation strategy.
What the source reports
- EnerPHit space-heating demand target≤ 25 kWh/m²/yrmodelled
- EnerPHit airtightness target≤ 1.0 ach @ n50measured
Measured means monitored data from the site. Reported is the publisher's stated figure. Modelled is a target or design figure rather than an outcome.
What we take from it
- An airtightness test at first-fix is non-negotiable in a deep retrofit. By the time plaster is on, fixing it costs ten times more.
- Heat recovery ventilation is what makes a tight house comfortable. Without it, a tight house is a damp house.
What the source does not tell us
- EnerPHit is a high bar. Most retrofit projects in the UK are not certified, and the database is a self-selected sample of the best work.