ABSTRACT

Indoor climate embodies those aspects of the hygrothermal environment, lighting, noise and air quality that influence requirements for comfort, health and safety. Interactions occur between the physical elements of the environment such that each component has to be critically considered in relation to its effect on the others, and this is so particularly when devising standards. For example, increasing window area with the intention of improving natural lighting can result in over-heating by increasing thermal gain from solar radiation, and conversely there will be increased heat loss from the built environment in cold external conditions. Another common example is the effect that thermal insulation of a building by draught-proofing can have in reducing ventilation and affecting air quality. Inevitably a ‘trade-off’ has to be made between such competing demands when setting comfort and health standards in housing design and construction. A satisfactory indoor climate also has a bearing on home safety; accidents are less likely to occur in well-lit, thermally comfortable surroundings. There now exists a considerable body of evidence to show that the design of buildings and features of the quality of the indoor environment exert a significant influence on the health of the occupants (Mant and Gray, 1986).