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Daylighting Resources - Productivity


Research has shown that people experiencing positive emotional states tend to be more productive (Wright and Cropanzano, 2000), and that positive emotional states can be reinforced by providing people with their preferred work environment. Since daylight is almost universally preferred to electric lighting, it is likely that increased use of daylight will support workplace productivity.

Job performance and psychological well-being

Job performance is closely correlated to psychological well-being, but not to job satisfaction. Psychological well-being is a short-term emotional response to a pleasant situation, whereas job satisfaction is a more rational, objective assessment of a person’s long-term attitude to their job (Wright and Cropanzano, 1997; Organ, 1988). For example, if employees experience happiness when they look out a window or sit in the sunshine, that feeling may contribute to their performance on that day, while not affecting how they feel about their co-workers, pay, or responsibilities.

Preference for daylight

There is no doubt that people find daylight more pleasant than electric lighting as their primary source of light. Wells (1967), Manning (1967), and Markus (1967) in the UK; Cuttle (1983) in the UK and New Zealand; Heerwagen and Heerwagen (1986) in the USA; and Veitch (1993) in Canada, have all shown that high percentages of survey respondents prefer to work by daylight. Similarly, people prefer to sit at desks that are beside windows rather than further back in the room, especially when those windows have access to direct sunlight (Markus, 1967; Aldworth and Bridgers, 1971; Collins, 1975; Ludlow, 1976; Cuttle, 1983; and Heerwagen and Heerwagen, 1986).

People’s preference for daylight may be partly due to their negative view of electric lighting. Cuttle (1983) found that people believe that working by daylight results in less stress and discomfort than working by electric light, and that working by electric lighting is deleterious to health, particularly in the long term. However, there is no scientific evidence to support any negative effects of electric lighting on long-term health.

Improvements in job performance

Hedge (1994) measured the performance of a clerical task on a computer in a room lit by different electric lighting systems, with and without windows. He found a small but statistically significant improvement in task performance when windows were present.

The windows provided more light than electric lighting alone, but the improvement in performance was greater than would have been expected due to the increase in light level therefore it seems to be attributable to an improvement in short-term psychological well-being, due to the presence of windows.

A survey of tenants of rented offices (BOMA, 1988) has shown that 2.1% of tenants think that the poor quality of their windows is the worst problem in their building, and that if the windows could be improved, an estimated productivity gain of 4% would result. This survey does not indicate whether dissatisfaction with windows was due to insufficient daylight, excessive glare, the presence of drafts, direct sunlight, or other factors associated with window discomfort.

Mood and satisfaction

Dasgupta (2003) found a small but statistically significant reduction in negative mood for people who worked for about 20 minutes in a private office with a large window during daytime; but no reduction in negative mood for the same people in the same office at night. Ruys (1970) also found that occupants of small offices disliked the absence of windows.

Some studies have suggested that people have an innate desire to be in contact with nature White and Heerwagen, (1998); windows provide a means for establishing visual contract with nature while at work. Heerwagen and Orians (1986) found that people occupying small windowless offices were much more likely to have pictures of natural scenes on their wall than were people with easy access to windows, possibly as a way of compensating for the absence of real natural scenes. An alternative explanation is that, in a small office, the view out the window may be the only source of environmental stimulation.

California Energy Commission
Connecticut Light & Power
Efficiency Vermont
Lighting Research Center
North Carolina Daylighting Consortium
Northwest Energy Efficiency Alliance
US Department of Energy