An energy performance certificate (EPC) gives a property an energy efficiency rating from A (most efficient) to G (least efficient) and is based on a complex calculation, which looks at a number of factors such as the age and type of building and its construction, insulation and heating systems. For more information on what an EPC is and when they are required, see Practice Note: Energy performance certificates (EPCs)—what are they and when are they required? The key regulations governing EPCs are the Energy Performance of Buildings (England and Wales) Regulations 2012, SI 2012/3118 (EPC Regs 2012) (as amended) and the Building Regulations 2010, SI 2010/2214, which implemented the requirements of the recast Energy Performance of Buildings Directive 2010/31/EU (recast EPBD directive). The EPC Regs 2012 apply to all buildings across England and Wales. Prior to the EPC Regulations 2012, the Energy Performance of Buildings (Certificates and Inspections) (England and Wales) Regulations 2007, SI 2007/991 (as amended) implemented the original Energy Performance of Buildings Directive 2002/91/EC (original EPBD directive). The