Modern learning and teaching is more personalised and diverse, resulting in pupils learning in a variety of spaces and in various ways. A dining area, for example, may be used for group discussion or individual reading; a circulation area, such as part of an atrium, could be used for informal tutoring or project work; and laptops could be used everywhere. It is important to find out in the early stages of briefing and design how spaces will be used by the school so that lighting flexibility is designed in.
In most types of buildings, users prefer rooms to have a day lit appearance during daytime hours. In schools, natural lighting during daylight hours should always be the main light source for reasons of quality of light and sustainability. Electric lighting and natural lighting should be complementary. Electric lighting will take over during the hours of darkness and should supplement natural lighting when it fades. To make sure that running costs and maintenance are reduced to minimum, light sources, luminaires and lighting controls need to be highly efficient, with a long life.
Pupils like spaces that are interesting and unique. They enjoy learning in them even though lighting conditions may not be ideal. There is a place for imaginative lighting environments in schools and this publication aims to encourage creativity, not create blandness or uniformity.
Health and safety
Learning and teaching rely upon good lighting. Although poor lighting is easily identified in use, it is often overlooked at the design stage. Our eyesight is resilient, so we may be unaware of the problems caused by poor lighting in our schools. Yet it can result in slower reading, poor posture, diminished concentration and long-term weakened vision. Lighting in schools is required not only for general safety but also for visual tasks. The two main issues to guard against are glare and flicker.
Glare
Glare is a common problem in the classroom. It occurs when a bright image (which is not the object one is trying to see) is seen either directly or by reflected light. This can cause significant difficulty with visual tasks. Although pupils try to compensate for glare by turning their heads or squinting, glare causes eyestrain and headaches and can sometimes be disabling. It can also cause loss of concentration and reduced productivity.
Glare can be divided into two types:
• Discomfort glare is not necessarily detrimental to vision but it produces feelings of visual discomfort.
• Disability glare occurs when a bright light source is close to the line of vision and makes the task more difficult to see. This problem is controlled by assessing the lighting installation in terms of its glare rating and ensuring that it does not exceed the recommended maximum.
Glare can be minimised by:
• The correct choice, orientation and positioning of the room furniture
• The use of internal or external blinds, which can reduce problems caused by excessive sunlight or daylight
• The use of louvers on fluorescent luminaires and/or the use of indirect lighting solutions, which will help reduce direct vision of the light source and therefore the instance of glare
• Correct choice of computer screen with anti-glare filters if necessary, together with orientation to avoid sunlight and daylight reflection
• Careful design of the luminance of the whiteboard relative both to sunlight and daylight glare and glare from luminaires.
Flicker
Flicker can cause discomfort or annoyance to some people. It can also produce stroboscopic effects with moving objects, which can be dangerous. For example, rotating machinery in a workshop can appear to be stationary. Epilepsy can be triggered by low frequency flashes of light, which can occur with some compact fluorescent lamps at ignition, or with discharge lamps towards the end of their life. Problems relating to balance, and some brain disorders, can also be exacerbated. All these can be avoided by using high frequency control gear.
Disability issues
Good quality lighting is important to help pupils learn, especially those with special educational needs (SEN) and/or any disability. Natural lighting with additional artificial light should be used where necessary, avoiding glare and revealing good visual contrast and colour rendering. Light levels should be adequate on the working plane and for people to clearly see the teacher’s face, the whiteboard and computers without creating reflections, shadows and harsh contrasts. For an even better effect, light sources should not be visible, flicker should be avoided and up-lighters should be used.
Hearing impaired people need to be able to see lip movements clearly, so the correct lighting level and direction are crucial. For example, if light is directed too much in a downward direction, it will produce harsh shadows, which will make lip reading difficult. The design of specialist accommodation for pupils with SEN and/or any disability is beyond the scope of this document and specialist advice should be sought. However, there are relevant design issues that should be considered for all schools:
• The colour rendering of the light source and the extent of contrast are particularly important. Some visual impairment involves a degree of colour blindness and it is important that contrast of tone as well as colour should be produced on the objects illuminated.
• Careful use of colour can help pupils recognise and identify objects. For instance, using a darker colour for a door frame (contrasting with door leaf and wall) will help in locating the door. A handle that clearly contrasts with the surface of the door and is non-reflective will also make it easier to distinguish.
• Students with visual impairment often require higher than normal levels of illuminance. It is not necessary to install this as a feature of the primary lighting system but provision should be available for supplementary task lighting.
Energy efficiency
The energy efficiency of artificial lighting depends on:
• The penetration of natural lighting indoors – if there is good daylight distribution in the classroom and good daylight levels, artificial lighting may not be required
• The luminaire efficiency and its electrical components, lamps and control gear
• The successful specification of the lighting controls, eg, their usability and response to changing conditions
• The operation, cleaning and maintenance regime.
