Indoor environments have strong positive effects on occupant well-being and functioning, especially attributes such as the amount and quality of light and color, the sense of enclosure, the sense of privacy, access to window views, connection to nature, sensory variety, and personal control over environmental conditions. Designing to enhance psychological well-being will therefore have positive impacts on work effectiveness and other high value outcomes, such as stress reduction, job satisfaction, and organizational commitment.
To reap the fiscal, physical, and psychological benefits of healthy buildings, projects must have a comprehensive, integrated design and development process that seeks to:
- Provide maximum access to natural daylight and views to the outdoors
- Provide superior ventilation
- Control sources of indoor air contamination
- Prevent unwanted moisture accumulation, and
- Enhance the psychological and social aspects of space.
Indoor environments also strongly affect human health. For example, the EPA estimates that the concentration of pollutants (like volatile organic compounds) inside a building may be two to five times higher than outside levels. A 1997 study by W.J. Fisk and A.H. Rosenfeld (Estimates of Improved Productivity and Health from Better Indoor Environments. Indoor Air Vol. 7, pp. 158–172) reports that the cost to the nation's workforce of upper respiratory diseases in 1995 was $35 billion in lost work plus an additional $29 billion in health care costs. The study estimates that more healthful indoor environments could reduce these costs by 10%-30%.
Provide Maximum Access to Natural Daylight and Views to the Outdoors
- Use a daylighting analysis tool to help guide the design process. See also WBDG Daylighting.
- Design windows to allow daylight to penetrate as far as possible into a room. Consider using light shelves (solid horizontal elements placed above eye level, but below the top of the window) to reflect daylight deep into a room. Design windows to provide views out from most spaces.
- Design for diffuse, uniform daylight throughout the room. Avoid glare. Avoid direct beam sunlight in continuously occupied spaces; however sun "spots" in other, shared or public spaces, are desirable and psychologically beneficial.
- Consider interior (shades, louvers, or blinds) and exterior (overhangs, trees) strategies to control glare and filter daylight.
- Consider shared daylight through glazed interior walls.
- Integrate daylighting with the electric lighting system. Provide controls that turn off lights when sufficient daylight exists. Consider dimming controls that continuously adjust lighting levels to respond to daylight conditions.
- Design floor plate depth to allow access to windows and views.
- Consider the security implications of window, glazing, and door locations. See also WBDG Designing Buildings to Resist Explosive Threats and Retrofitting Buildings to Resist Explosive Threats.
Provide Superior Ventilation
- Design the ventilation system to exceed ASHRAE Standard 62: Ventilation for Acceptable Indoor Air Quality.
- Minimize recirculation while assuring energy efficiency through energy recovery. See also WBDG High-Performance HVAC.
- Ensure that ventilation air is effectively delivered to and distributed throughout the 'breathing zone.' Consider individual controls.
- Provide local exhaust for restrooms, kitchens, janitor's closets, copy rooms, etc.
- Consider installing CO2 sensors to provide real time monitoring of air quality.
- Consider separating thermal conditioning from ventilation in order to vary delivery of air volume separate from temperature for better comfort.
- See also WBDG Natural Ventilation.
Control Sources of Indoor Air Contamination
- Test the site for sources of contamination: radon, hazardous waste, fumes from nearby industrial or agricultural uses. See also WBDG Air Decontamination.
- Locate air intakes away from sources of exhaust fumes (e.g. from buses, cars, or trucks).
- Consider security implications of the location of building air intakes.
- Consider recessed grates, "walk off" mats, and other techniques to reduce the amount of dirt entering the building.
- Specify green products and materials and furnishings that are low emitters of indoor air contaminants such as volatile organic compounds (VOCs).
- Allow adequate time for installed materials and furnishings to "outgas" before a new workplace is occupied. Assist the process by running the HVAC system continuously at the highest possible outdoor air supply setting after materials and furnishings have been installed to adequately "flush out" the facility. (The exact timing may vary for different materials and different environmental conditions.)
- Consider "modular zoning" for air distribution in order to avoid cross contamination, including providing mail handling center with a separate ventilation system.
- Install proper barriers between occupied and construction zones in renovation projects in order to protect worker health.
Prevent Unwanted Moisture Accumulation
- Design the ventilation system to maintain the indoor relative humidity between 30% and 50%.
- Design to avoid water vapor condensation, especially on walls and the underside of roof decks, and around pipes or ducts or windows.
- Design buildings with proper drainage and ventilation.
- See also WBDG Mold and Moisture Dynamics and Air Barrier Systems in Buildings.
Enhance the Psychological Effects of Space
- Design to allow workers to move freely from solitary work to group action as work requires.
- Provide mobile technologies (phones, computers, wireless connectivity) that support new work styles and work practices.
- Design to reduce stress and facilitate mental rest breaks.
- Provide workers the means to make meaningful changes in their immediate environments (e.g. through personalization and control over the immediate environment to the extent possible).
- Provide spatial features that support visual and acoustical privacy but allow opportunities for informal encounters.
- Provide an interesting visual environment and, at the same time, design for a balance between visual access and visual enclosure. Provide views of natural vegetation, indoors or outdoors, when possible.
Building / Space Types
Accessible, Aesthetics, Cost-Effective, Functional / Operational, Historic Preservation, Secure / Safe, Secure / Safe—Ensure Occupant Safety and Health, Secure / Safe—Provide Security for Occupants and Assets, Sustainable, Sustainable—Use Environmental Preferable Products, Sustainable—Enhance Indoor Environmental Quality, Sustainable—Optimize Operational and Maintenance Practices
Provide Maximum Access to Natural Daylight
- Daylighting Performance and Design, 2nd Edition by Gregg D. Ander. Wiley, 2003.
- Illuminating Engineering Society
- Lawrence Berkeley National Laboratory
- Lighting Research Center, Rensselaer Polytechnic Institute