Ventilation Building Regulations
All domestic ventilation installation are required to meet the following regulations by law. Building regulations document F can be downloaded here.The below extract applies to Ventilation rates for Bathrooms, Kitchens Utility rooms etc:
IEE Regulations for Bathrooms
Failure to follow regulations relating to electricty in the bathroom can be fatal
The previous IEE 16th Edition identified zones within the bathroom to illustrate what type of electrics in the bathroom can be used or installed, and these have been updated in the 17th Edition. These zones take into account windows, doors, walls ceilings and partitions, assessing the level of risk in each zone, with specific requirements governing the type of equipment deemed safe to be used in each. Zones 0-2 are considered the wettest, and the former zone 3 is no longer defined.
PELV and SELV
Electrical products may also be identified as as PELV - Protective Extra-Low Voltage, low voltage but connected to earth, or SELV - Separated Extra-Low Voltage, low voltage but with output isolated from the input. SELV products can be used in any zone in the bathroom providing the source, such as the transformer, is located beyond Zone 2.
It is good practice to use CE & Safety Certified Products as they are tested according to all appropriate electrical standards, with factory inspection and ongoing product surveillance and specific test programmes related to their performance in damp and wet environments. For installations in the bathroom electricians should look for the UK's two most common safety certification marks - the ASTA Diamond Mark and the BEAB Approved Mark.