How to improve your EPC rating: cheap improvements for landlords

The bigger-ticket measures that move whole bands

Crossing from one band into the next — particularly out of F or G, or from D into C — usually requires one of the larger structural measures rather than a combination of small fixes alone. Cavity wall insulation, where the property has an unfilled cavity, is typically the single most cost-effective larger measure because uninsulated cavity walls are a major heat loss route and filling them is comparatively affordable and quick. Solid wall insulation (internal or external) addresses the same problem in pre-1930s properties without a cavity but costs considerably more and is more disruptive. Replacing an old, inefficient boiler with a modern condensing model, or upgrading single glazing to double glazing, both deliver meaningful score improvements but at a materially higher cost than the fabric-only measures above.

Where heat pumps and solar PV fit in

Air source heat pumps and solar PV can both improve an EPC score, but they work best — and score best — when the building's fabric is already reasonably efficient. A heat pump installed in a poorly insulated property with old radiators sized for a gas boiler can struggle to deliver the flow temperatures needed for adequate heating, and the software will reflect this in a more modest score improvement than the same heat pump in a well-insulated home with appropriately sized emitters. The general sequencing principle — insulate first, then consider low-carbon heating — applies as much to EPC scoring as it does to running costs and comfort in practice.

• Improve wall, loft and glazing performance before installing a heat pump
• Check radiator sizing is appropriate for lower flow temperatures
• Solar PV may affect the modelled rating; confirm roof rights and property-specific suitability
• Battery storage paired with solar PV can add further benefit depending on the software version used

Documentation: the improvement that costs nothing

One of the most overlooked ways to improve a score costs nothing at all: making sure evidence of work you've already had done is available to the assessor. Cavity wall insulation, loft insulation top-ups, double glazing installed under FENSA certification, and boiler replacements with Gas Safe or building control sign-off can all be recorded more favourably when documentary proof exists, because the assessor otherwise has to rely on a visual inspection alone and, in cases of doubt, apply a more conservative default assumption. Dig out any paperwork before the assessment rather than after.

A sensible order of operations

For most owners and landlords working to a budget, the sensible order is: get a current EPC and read the recommendations report, gather documentation for anything already done, complete the cheap fixes (loft top-up, cylinder jacket, heating controls, lighting), then assess whether a single larger measure — most often cavity wall insulation where applicable — is needed to cross the next band threshold. Only after the fabric is reasonably sound does it make sense to consider a heat pump or additional glazing work purely for EPC purposes, since fabric-first sequencing gets the best return at each stage.

Re-assessing once work is done

Improvement work only affects your legal position once it's reflected in a current, valid EPC — carrying out the work without a fresh assessment leaves your official rating unchanged on the Register. This matters most for landlords needing to clear the MEES minimum standard before a letting can proceed, since an outdated certificate showing band F does not become band D simply because the wall insulation has since gone in.