Lighting Impact on Occupants
Lighting in the workplace can be better understood as an ecosystem that includes lighting design as just one component of a network of interrelated considerations. The ecosystem framework offers a comprehensive approach to optimize visual comfort, as well as enhance occupant well-being and organizational performance in the workplace. The three primary components of the Lighting Ecosystem are:
- Lighting Design: includes factors such as electric lighting, controls, daylight penetration, and lighting solutions that integrate daylight and electrical light sources.
- Interior Design: includes factors such as furniture, office layout/juxtaposition, colors, finishes, and computer ergonomics.
- Organizational System: includes factors such as organizational culture, occupant behavior, nature of work, and technology used in the workspace.
This third component - the Organizational System - is often misunderstood or overlooked when lighting decisions are being made. Organizational Systems are just as important as Lighting and Interior Design decisions. For instance, an organizational mission may necessitate a high degree of security and confidentiality, resulting in a lighting strategy that specifies limited daylight exposure in the primary workspaces. An effective lighting solution should support organizational mission and culture, and also deliver lighting for optimal task performance and occupant health and wellbeing.
Stimulating circadian systems with electric light requires advanced planning to be effective. The provision of electric light should supplement, not replace, the maximum amount of daylight that is otherwise being provided in the workplace. Further, too much electric light towards the end of the day can also be detrimental. Receiving shorter wavelength (blue) light from computer monitors or other “cool” light sources at night near bedtime can disrupt a person’s circadian system and delay sleep, which can cause both psychological and physiological problems the next day. While electric lighting which “tunes” or adjusts the spectrum of light throughout the day can sometimes be optimal, it is not necessarily required where occupancies do not accommodate extended or shift work. Lighting sources should be specified which are appropriate to the task and stimulation required.
As daylighting analysis can evaluate natural light sources, electric light modeling can also evaluate the impact of electric light sources and the effect of interior space planning, such as the location of rooms and furniture, on a lighting strategy. Modeling can provide critical information regarding visual acuity levels on the horizontal plane, as well as circadian exposure on the vertical, in a variety of working conditions. With effective modeling, a balanced approach to energy efficiency and occupant health and comfort can be achieved.
The analysis is valid only to the extent that it is accurately based on the condition variables in the workplace. Accordingly, a lighting analysis is best conducted by a professional lighting consultant who is cognizant of these various factors and the way they interact with each other.
Happier and more comfortable occupants tend to miss fewer days of work and perform at sustained levels when approaching tasks throughout the day. Providing personal controllability of lighting sources in task areas permits occupants to perform better under desired conditions. Creating balanced illumination levels through a combination of indirect/directing lighting strategies eliminates distracting shadows, allowing for occupants to work more productively. Likewise, creating visually stimulating and engaging lighting environments in non-workstation like corridors and walkways by varying light intensities and contrasts can reenergize passing occupants. A positive lighting impact on human productivity can further provide some of the largest financial benefits within the office as well.
Creating a sustainable and well-functioning lighting strategy by integrating efficient lighting technologies, controls, and space layout has been shown to additionally increase overall satisfaction and comfort in the space itself.
According to a study done by the Light Right Consortium:
- Lighting designs that provided direct and indirect lighting, wallwashing, and occupant dimming controls were rated as comfortable by 91% of the occupants.1
- In the same study, significantly fewer occupants (69-71%) reported their working space as comfortable when only 2x4 downlight troffers were provided.
Additionally, occupants find their space to be more aesthetically pleasing – and with fewer negative health implications – when the lighting system is well integrated into the whole building environment. View the SF Tool Comfort case study.
1. Light Right Consortium Study, Summary of Findings
Poorly designed lighting systems, characterized by uncomfortable fluctuations in luminance levels or excessive glare, causes visual discomfort and leads to eye strain.
Integrating a successful lighting system ensures these negative side effects are avoided and promotes an overall healthier environment for occupants. Furthermore, providing maximum access to natural light and views to the outdoors has shown to promote both physical and mental health by increasing the body’s internal production of vitamin D, avoiding some of the causes of depression. Read about the health affects of daylight on the Buildings and Health page.
Lighting plays an important role in the safety of humans within and outside of the building. Emergency lighting must efficiently direct occupants during power outages. Similarly, exit signage must visually highlight escape routes throughout the building during all operational hours. Outdoor lighting can be utilized to deter crime and illuminate dangerous areas, allowing occupants to move safely around the building in the early mornings or evenings.
Best Practices and Strategies
|Design windows to allow daylight to penetrate as far as possible into the space. Consider using light shelves to reflect daylight off the ceiling and deep into the room. Design windows to provide views to the outdoors for a majority of occupants.
||Avoid direct beam sunlight in continuously occupied spaces to minimize direct glare. However, designing for contrasting light levels, or sun “spots”, in corridors or public spaces can be psychologically revitalizing and therefore beneficial.
||Control uncomfortable glare and heat gain using internal shading devices such as louvers, shades, or blinds and exterior shading strategies such as overhangs or vegetation.
|Provide occupants with ways to make meaningful changes to their lighting environments through personalization of task lighting and manual overrides over automatic lighting controls.
||Couple indirect and direct lighting fixtures to create a well-balanced illuminated work environment without uncomfortable shadows.
||Use light colored paints on vertical surfaces and ceilings that reflect more light to create the perception of a warmer and brighter space.
|Create a visually interesting lighting environment by providing flexibility (coloring, quantity, quality, and source).
||Periodically test and monitor emergency lighting to ensure proper functionality.
||Adhere to all outdoor lighting codes and regulations regarding human safety. Survey occupants on their feelings of security during evening hours and adjust outdoor lighting levels accordingly.
|Design work space options to include access to daylight to synchronize circadian rhythms.