This guidance is aimed at homeowners and those managing or renting historic or older domestic buildings who may need to commission an Energy Performance Certificate (EPC) or who have received one for an older property that has been purchased or rented. Details are provided on the type of information included in an EPC, how it is calculated, and its limitations as an assessment method when applied to older buildings. The guidance also covers the issues to be taken into account when commissioning an EPC and considering its recommendations. Almost every older building can accommodate some energy improvements without harming either its special interest or environmental performance. However, an appropriate balance needs to be achieved between building conservation and measures to improve energy efficiency if lasting damage is to be avoided both to a building's character and significance and its fabric.