An Energy Performance Certificate (EPC) is only required when a building is constructed, sold or rented out. For the purposes of the regulations, a building is defined as ‘a roofed construction having walls, for which energy is used to condition the indoor climate, and a reference to a building includes a reference to part of a building which has been designed or altered to be used separately’. For a building to fall within the requirement for an EPC it must have a roof and a wall and use energy to condition the indoor climate. Services considered to condition the indoor climate are the following fixed services: heating, mechanical ventilation or air conditioning. Although the provision of hot water is a fixed building service, it does not condition the indoor environment and would not, therefore, be a trigger for an EPC. The same argument applies to electric lighting. Where a building is expected to have heating, mechanical ventilation or air