Electrical appliances such as lights, heaters, and heated towel rails, generally need to be installed as fixtures, with permanent connections rather than plugs and sockets. The installation of electrical devices in bathrooms and shower rooms is regulated in Section 601 of BS 7671, and Part B of the Building Regulations.
Zone 0 is the smallest cuboid volume that contains the bathtub, shower basin.
Zone 1 is the area above Zone 0, up to a height of 2.25 m above the floor.
Zone 2 is the area above Zone 1 up to a height of 3 m, as well as the area that is horizontally within 0.6 m from Zone 1.
Zone 3 is the area above Zone 2 up to a height of 3 m, as well as the area that is horizontally within 2.4 m from Zone 2.
