Lighting is of critical importance in all types of buildings. An adequate level and distribution of light is vital if visual tasks are to be carried out safely and effectively. Good lighting will also improve the internal environment and appearance of a building. The use of efficient lamps, ballasts and luminaires, with appropriate lighting controls, can provide the right visual environment, be energy efficient and cost effective. Part 1 of this Good Building Guide describes the general principles and gives an introduction to what is available. Different types of lamps are described and compared in relation to their efficacy, economic life, dimming control, re-strike time, colour rendition, comparative installation costs and comparative operating costs. 8 pages.