Lighting in schools.

  • Department of Education and Science
Date:
1967
Catalogue details

Licence: Public Domain Mark

Credit: Lighting in schools. Source: Wellcome Collection.

    14/84 page 6
    Technical drawing, and particularly tracing, is best performed under a high level of illumination with the minimum direct or reflected glare. Normally general overhead lighting will be sufficient, but for advanced work an adjustable light at the board may be preferred (paragraph 181). eyes. The danger is that bad lighting can retard the process of learning by making concentration more difficult and by hastening the onset of tiredness dur- ing the day, through the physical and mental strain of trying to see under unfavourable conditions. 29. For these reasons it is most important for the architect to understand the limitations as well as the range of human vision, and from this to be able to create the conditions under which the eye can per- form best, with as little effort as possible. The visual task 30. The essentials of the task that a school child’s eyes have to do lie in making out the key features of the scene which is being observed by distinguishing differences in shape, position in space, texture, colour and brightness. The eyes have to supply the brain with sufficient information for it either to be able to recognise objects already familiar from pre- vious experience or, if the objects cannot be identi- fied precisely, then to provide enough clues for an intelligent guess at their nature to be made. 31. The visual difficulty of the work will vary widely. It may be relatively straightforward, as in reading a clearly printed book. It may be very much more difficult as, for example, when trying to trace accur- ately over a faded engineering print (photograph 5), or to differentiate between two colours which are very close, or to align precisely the markings on a vernier scale (photograph 6). The visual task may be one that has to be done very quickly and without the chance of retracing one’s steps, such as when sight-reading music (photograph 7). The object, observed may be stationary or it may be moving fast as when trying to follow the rapid movements of a P.E. instructor demonstrating a handspring (photo- graph 8). The task may be only intermittent or it may be one requiring sustained visual concentration. Clearly the nature of the visual task which is being undertaken will determine both the quantity and the quality of light that should be provided if the work is to be done easily. Quantity of light General note 32. The general rule is that the more difficult the visual task, the greater is the amount of light that should be provided to allow the job to be done efficiently. If work has intricate and small-scale detail, lacks contrasts of light and dark or of colour, has to be done very quickly or requires sustained attention, then it will be carried out more easily under a high level of illumination, always providing the lighting is of commensurate quality. Thus pupils in a needlework room or in a technical drawing office will benefit from a higher level of lighting on their work than they would require in a general-purpose class- room. Recommended levels of illumination 33. Regulation 52(2) of the building regulations requires that ‘In all teaching accommodation and kitchens the level of maintained illumination and the daylight factor, on the appropriate plane in the area of normal use, shall be not less than ten lumens per square foot and 2 per cent respectively’. This is the minimum permitted: to ensure that none of the work- ing areas in the room falls beneath this, it is necessary to design for a higher average level of illumination. The reason why this level was chosen as the mini- mum was that research work had shown that at least four-fifths of school children achieved a good stand- ard of vision at 10 Im/ft? and could see well enough to do normal school work such as reading ? inch high writing on a chalkboard at a distance of 30 feet. Below this level of illumination visual acuity fell away rapidly. Above 10 lm/ft? it was found that visual performance did not improve proportionately with increases in the level of illumination. 34. At the same time it is worth bearing in mind that a visual task will be made easier by an improvement in any of its aspects, for instance, by an increase in the contrast or size of the details. Moreover, such improvements will increase the ability to see more
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