Conservation of fuel and power: Approved Document L, Volume 2 — Buildings other than dwellings

O N L I N E V E R S I O N L1(b), L2 6.60 Lighting should observe the following. a. If it is general lighting, either: i. have an average luminaire efficacy of 95 luminaire lumens per circuit-watt ii. the Lighting Energy Numeric Indicator (LENI) method, following Appendix B. b. If it is display lighting, any of the following: i. have an average light source efficacy of 80 light source lumens per circuit-watt ii. have a rated power usage no greater than 0.3W/m2 in each space iii. the LENI method, following Appendix B. c. For high excitation purity light sources, an average light source efficacy of 65 light source lumens per circuit-watt. NOTE: This approved document does not include minimum standards for specialist lighting, such as theatrical spotlights, stage lighting, gobo projectors or wall-washers. 6.61 General lighting and display lighting should be metered by one of the following methods. a. Dedicated lighting circuits with a kWh meter for each circuit. b. Local power meter coupled to or integrated in the lighting controllers of a lighting management system. c. A lighting management system that can both: i. calculate the consumed energy ii. make this information available to a building management system. Lighting controls 6.62 Lighting controls in new and existing buildings should follow the guidance in the Building Research Establishment’s Digest 498. 6.63 Unoccupied spaces should have automatic controls to turn the general lighting off when the space is not in use (e.g. through presence detection). Occupied spaces should have automatic controls where suitable for the use of the space. 6.64 General lighting in occupied spaces should have daylight controls (e.g. photo-switching and dimming) for parts of the space which are likely to receive high levels of natural light. 6.65 Display lighting should be controlled on dedicated circuits that can be switched separately from those for lighting provided for general illuminance. Building automation and control systems 6.66 If a new building has a space heating or air-conditioning system with an effective rated output greater than 180kW, a building automation and control system should be installed. 6.67 If an existing building has a space heating or air-conditioning system with an effective rated output greater than 180kW, a building automation and control system being replaced or installed should follow paragraphs 6.72 and 6.73. NOTE: The requirements in paragraphs 6.66 and 6.67 also apply to buildings containing heating and air-conditioning systems which are combined with ventilation systems. 53 Building Regulations 2010 Approved Document L Volume 2, 2021 edition O N L I N E V E R S I O N