This Guide is intended for contractors who carry out electrical installation work in dwellings, including houses and flats. It provides information and guidance relating to the design, construction, inspection, testing and certification of domestic electrical installation work, and is intended to promote good practice and aid understanding of the fundamental concepts of protection for safety. The guidance is based on the requirements of BS 7671 2018 Requirements for Electrical Installations, and references to Regulation numbers are to those contained in that Standard. sakriti opis