Estimated outcome
Annual savings
£0
Simple payback
0 years
Annual CO₂ reduction
0 kg
Comfort improvement
Moderate
Installer route
Scenario notes
Methodology
How loft insulation savings are estimated
This tool uses a UK baseline from Energy Saving Trust style benchmark savings for a gas-heated semi-detached home. In line with the brief, the model assumes an upgrade from 0 mm to 270 mm can save about £580 a year, while moving from 100 mm to 270 mm saves about £135 a year. Intermediate depths are interpolated and then adjusted for home size, fuel tariff, and regional heating demand.
Deeper upgrades beyond 270 mm show diminishing returns rather than linearly repeating the first gains. Comfort ratings and DIY guidance are based on the amount of extra material needed and the practical complexity of achieving safe, even coverage around services and loft access.
Related guides
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