Carrying out upgrades and then having the new certificate bounce back at the same rating is a maddening outcome. The reasons it happens are usually predictable.
No documentary evidence of the work
Assessors can only credit work they can see or verify. Loft insulation laid years ago, with no receipt or photo, may not be counted.
A poor original assessment
Sometimes the issue is the previous certificate, not the new one. If the original assessor missed something, the upgrade only restores the points that should already have been there.
Conservative defaults
Where evidence is missing, EPC software falls back to conservative assumptions. Keep documentation of every upgrade carefully — it is the difference between a confident re-rating and a disappointing one.
