The EPC is a running-cost model GOV.UK SAP⁠, so the measures that move it are the ones that cut modelled spend on heating, hot water and lighting. That is why insulation and heating controls punch above their price, and why some expensive improvements barely register.

The order that usually wins

1. Fabric first

Heat that never escapes is the cheapest heat. Loft insulation top-ups and cavity wall insulation (where the walls are suitable cavities) are the classic first moves for the 1930s semi, and both appear near the top of most certificates' recommendation lists GOV.UK⁠. Draught-proofing is small but cheap.

2. Controls second

A thermostat, thermostatic radiator valves and a programmer let the model assume less waste. For homes that lack them, controls are routinely the best points-per-pound on the list.

3. The big-ticket items

Replacement boilers, heat pumps, solid wall insulation, floor insulation and double or triple glazing move bands but cost serious money. Whether they are worth it depends on the gap you need to close and, for landlords, the £10,000 cost cap that frames the 2030 obligation Gov response Jan 2026⁠. Energy Saving Trust maintains measure-by-measure guidance Energy Saving Trust⁠.

4. Generation last

Solar panels add points and are how B homes reach A. For a D-rated house they are rarely the first move, because fabric problems remain unfixed underneath.

Why we publish no cost table here

Measure prices vary by property, region and installer, and we could not verify a current national price list against a primary source at the time of writing. Rather than print stale or invented figures, we point you at two things that are accurate for your house: the indicative costs printed on your own certificate's recommendations GOV.UK⁠ and quotes from installers. Any figure elsewhere on this site carries a source seal; absence of a number here is deliberate.

Protect the points you buy

Under RdSAP 10, assessors need evidence Elmhurst RdSAP 10⁠. File every invoice and installation certificate, or your new insulation may be invisible to your next assessment. Then, when the works are done, see what happens in the assessment and check where you stand with the letting checker. Landlords planning against the deadline should read EPC C by 2030 and the band C and band D dossiers.