LETI Climate Emergency Retrofit Guide
A widely cited industry guide that defines what 'good' retrofit looks like for UK homes, with worked case studies of every common archetype.
Source
Summarised from Low Energy Transformation Initiative, 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.leti.uk/retrofitThe problem
Until LETI's guide, the UK industry had no shared target for what a climate-aligned retrofit should achieve at home level. Without targets, retrofits were optimised against budget rather than against a future that needs the building stock at near-zero carbon.
What they did
LETI sets numerical performance targets across space-heating demand, peak load and embodied carbon, then publishes case studies showing how typical UK archetypes meet them. The guide is written for designers and decision-makers, not for product sales.
What the source reports
- Space-heating demand target for retrofit≤ 30 kWh/m²/yrmodelled
- Peak heat load target≤ 20 W/m²modelled
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
- A clear performance target changes which order you spend money in. Without one, the heating system always wins the budget and the fabric loses.
- Peak load matters as much as annual demand. It determines whether a heat pump fits at all.
What the source does not tell us
- Targets describe where the stock needs to get to, not the cheapest first step for any individual home.