All newly constructed or converted residential properties in the UK require an On Construction Energy Performance Certificate (OCEPC) before occupation, as part of the final sign-off process from Building Control. The On Construction Energy Performance Certificate rates a property’s energy efficiency on a scale from A to G, with A being the highest rating. The new build EPC is generated from a comprehensive SAP Calculation for the dwelling, which also helps demonstrate compliance with Part L1A or Part L1B of the Building Regulations (or regional equivalent).Only an accredited On Construction Energy Assessor can issue a SAP EPC, and the certificate remains valid for 10 years for future sale or letting of the property.