Guide B1: Heating deals with the selection, design, commissioning, operation and management of most types of heating systems in buildings. It deals specifically with non-domestic buildings, though much of the contents will apply to domestic communal heating. Such systems provide space (including ventilation) heating and/or hot water services and installations such as swimming pools. Virtually every building (outside the tropics), contains a heating system. In most cases its primary purpose is to produce acceptable levels of thermal comfort – paramount for the health and wellbeing of building occupants and provide domestic hot water – or to protect the building fabric or its contents.