Workplace Lighting

Workplace productivity

Workplace productivity tends to focus, understandably, on job-related problems and improving methods of turning out the product or service workers are employed to deliver. Mostly, employers are broadly aware too that environmental factors like staff catering/rest-room facilities, heating and similar creature comforts, also make a positive contribution to productivity. Even so, any role lighting may have to play in workplace productivity is sometimes limited to a nodding acquaintance with statutory requirements around the 'reading in the semi-dark is not good for your eyes' level.

However, plenty of research evidence suggests lighting does have a significant impact on employees – and thus their productivity. As a result, employers may wish to consider whether the impact of poor office lighting, for example, affects the business more broadly than is currently understood, and whether lighting improvements, in addition to upgrading the office environment, may have commercial advantages too. 

Light and visual performance

Your visual performance depends on both the quality of lighting and your own 'seeing ability'. Whilst lighting quality in any location is fixed, 'seeing ability' nevertheless decreases markedly with age. So a borderline light quality which may just be acceptable for the 20 – 30 age range, may be entirely unsuitable for employees who are in the 40 – 60 age bracket. With changes in retirement age already under way, we are likely to see the typical working life increasing, and this ageing workforce has implications for companies.

Improvements in lighting quality have been shown to improve productivity, usually resulting in an increased volume of work completed, and with fewer mistakes. As would be expected, the most visually demanding tasks showed the greatest productivity increases.

Light and the work environment

Good lighting has a stimulating effect on workers, whereas poor lighting hampers performance, for example, by causing glare, or making colour recognition difficult. Either extreme is harmful: dim lighting can result in headache and eye strain, whilst harsh lighting does the same and makes proper focusing much more difficult.

Light and human biology

Light is the essential component of human vision, and vision is the sense we all use most to understand the world around us. Outdoor and indoor light also affect our body clock, both at a seasonal (circannual) and daily (cicadian) levels, influencing our mood, behaviour, functioning and alertness. Research tells us office workers generally prefer additional lighting even where there is plenty of daylight, and actually stay more alert when lights are brighter.

General brightness in summer, where extra daylight boosts indoor levels, has a positive stimulating effect on workers. Though reducing daylight in winter has negative effects, bright indoor lighting can go a long way to compensate.

Flicker from some types of fluorescent light, usually caused by lights which operate at lower frequencies, is known to cause stress and visual discomfort. In fact, studies recognise that fluorescent lighting in general is inclined to make workers sleepy, mostly later in the day. Where this is likely to be a problem, allowing frequent outdoor breaks helps to counteract this and increases alertness. 

Natural light

Scientific study again shows worker levels of satisfaction and general well-being are directly related to the number of windows in the workplace environment. Where renovations have created more natural light, illness and absences have declined, resulting in a happier and more productive workforce. So the clear message is that innovative lighting approaches which maximise natural light will always have positive effects on worker motivation and commitment. 

Strategies and solutions

Offices are expensive to run, but around 80 per cent of the total expense is staff costs. This means any investment which helps to develop a more motivated and creative workforce actually pays for itself. For example, survey evidence tells us an attractive room with good lighting makes it easier for employees to positively identify with their company.

General lighting 

Fluorescent tubes are relatively inefficient for lighting modern buildings and are fast being replaced by triphosphor tubes as retro-fit replacements. These offer more light, excellent colour rendering, plus longer life and energy savings, making them a good upgrade choice for older lighting systems.

LED light sources are also emerging as a new lighting technology for general lighting in office buildings where their use as ceiling luminaires makes an excellent lighting choice. These too provide economic benefits in terms of long life and low costs.

In large open areas, an adaptable lighting system can use light to create 'rooms' of varying light intensities for different tasks and purposes, and, with a suitable control system, can quickly change and reformat these layouts.  Whatever your lighting-control system, allowing workers local control of lighting in open-plan buildings always raises levels of job satisfaction, and also reduces stress. 

Task lighting 

Effective task lighting is a vital form of support for workers and is an area where sophisticated planning pays off. More complex and detailed the task need the most illumination. For example, a general area may be illuminated at perhaps 300 lux, a corridor area at 50 lux, whilst working on an architectural drawing may require a lighting level of 750 lux – 15 times more light than a corridor.

In office contexts, easily adjustable desk and table lights are a good choice for task lighting. Where access to filing cabinets or bookcases is required, directional spotlights, ceiling downlights or a LED lighting strip may be best for illuminating these type of areas.

A frequent cause of display-screen glare is the effect of directional light bouncing back off the screen's reflective surface. The use of glare filters, blinds and up-lighting as appropriate can help to cope with this problem where it is not possible to redirect the light source or re-position the screen.

Sources of light invariably have a dominant 'colour' – sodium, for example, can make diagrams and texts difficult to read, whereas bright cool white light imitates daylight and thus encourages alertness. This kind of information can often be used to plan different lighting zones. Busy work zones could perhaps use lighting above standard requirements to prevent distraction, whilst staff rest areas might use soft, warmer lighting instead to produce an environment in which it is easier to wind down.

Abrupt changes of lighting which require sudden visual adjustments should be avoided if possible. Workers will always appreciate a more gradual change. 

Ambient lighting

Beyond the strict requirements for adequate light to complete visual tasks, decorative ceiling, wall, and picture lights can help to create a pleasant and attractive work environment which helps to lift everyone's mood.

At the cutting-edge of contemporary lighting research, scientists have used LED-equipped ceiling tiles to create an office with its own 'blue sky' ceiling – complete with its own occasional rolling clouds! This research is testing the assumption that human minds are 'programmed' to perform tasks most efficiently under an open sky. Preliminary results show workers find this so-called dynamic lighting 'extremely pleasant'. So perhaps the blue-sky thinking in offices of the future might really be done under blue skies.