Your EPC rating: what it says, what it misses, and how to actually use it

Your Energy Performance Certificate is one of the most influential documents in retrofit. Not because it is perfect, but because buyers, lenders, and grant schemes use it as a shared reference point.

The rating is derived from a model of your home's fabric and systems. It can miss some day-to-day factors, but it still helps highlight where upgrades are likely to have the biggest impact.

For homeowners, the practical takeaway is simple: use the EPC as a map, then validate assumptions on site with a proper survey and a whole-house plan.