In Britain where the sun is all too rare the answer must clearly be one of welcome, and an early decison when an architect is planning the orientation of his building is to encourage the entry of sunlight. Sunlight adds to the overall level of light when it is available, and adds to those other environmental factors such as variety and change, modelling and the creation of delight.

Sunlight effect in Britain

There is a different level of experience when getting up in the morning to a sunlit world, as experienced from the interior of a building, and it is important that an element of sunlight is available for some part of the day. Architects have used the sunlight effect in buildings to create a specific atmosphere, as for example the shafts of light entering the south side of our great cathedrals; and on a much smaller scale the use in houses of daylight and sunlight entry from above to provide necessary functional light to interior areas, where otherwise little natural light would be available.

The impression of sunlight is also important seen from windows which themselves admit no sunlight, but where the view of a sunlit landscape or buildings may be enjoyed. Whenever sunlight is available there is a strong desire to perceive it, and disappointment when it is unnecessarily excluded. There is of course the obverse side associated with heat gain and glare, depending upon the orientation of the glazing, and whether people working in a building are confined to a fixed position.

The effects of direct sunlight can be a disadvantage. Some control may be required in certain circumstances at certain times of year, and as far as heat gain is concerned this is best done beyond the window, and is of a sufficiently flexible nature to be available only when required, or if fixed, not to inhibit the view.

One of the methods adopted to control the glare effect is to use forms of glazing which cut down light transmission; these need to be treated with care to avoid the impression that the interior of a building is permanently dim, and some glazing is available which reacts to the external light available, only cutting down the light when the sunlight is too bright, and might cause glare. To sum up, the need for the admission of sunlight is important, the architect must consider this as a first requirement in planning the location and layout of the building, but in certain circumstances controls will be needed.

Whilst the colour of daylight will vary from morning to evening, and with changes in the sky and weather patterns; it is always regarded as the reference by which colour is judged daylight is regarded as ‘real colour.’ In early stores, such as Harrods, voids were opened in the roof to admit daylight to sales areas below; whereas for some years this was ignored. There were several reasons for this, not least being that it was considered that means of artificial light were more suitable for display, to show off the goods ‘in a better light.’

This tended to ignore the environmental advantages of daylight and natural colour, and this has since been recognized in many new large shopping areas, where the entry of daylight is encouraged for the provision of environmental light to the store, but where for display purposes artificial light may be introduced locally to enhance the product. The old concept of ‘taking something to the light’, by which was meant daylight, may be less of a necessity if the environmental light gives natural colour; whilst from the point of view of the shop worker who must remain in the same environment all day the advantage of natural light is obvious.

The same applies to office buildings, where people tend to have to stay in the same atmosphere all day; if workers are too far from a window and the impression of natural light is greatly reduced, there is a sense of dissatisfaction. This is recognized by management, ensuring that for a part of the working day, for example during coffee breaks or in the office dining room, there is access to daylight, a change of environment. It is generally recognized that vision is enhanced by good contrast, and that the natural colour of daylight increases contrast; it is argued that this permits lower illumination levels, whilst increasing visibilit