Provide access to indoor light exposure and light education.
This WELL feature requires projects to ensure appropriate light exposure in indoor environments by using daylighting or electric lighting strategies. To encourage users to seek light exposure on their own, projects are required to provide users with education about the importance of light for health.
Mammals function on an approximately 24-hour cycle, following what are referred to as circadian rhythms. Light is the main driver of the circadian system, which controls body processes such as digestion, the release of certain hormones, body temperature and sleep.
Humans evolved their sleep schedules to be dependent on the natural day-night cycle. Electric light has only been widely used as a source of light for less than 200 years. The increase in the use of electric lighting has led to indoor environments relying on electric light over daylight. However, reduced exposure to light has been linked to the onset of depression and impairment of cognitive function in individuals. Irregular sleep-wake cycles have been linked to poorer academic performance in college students. Depression is a common illness worldwide, with more than 300 million people affected. Studies have shown that light exposure during daytime has been linked to increases in productivity and sleep quality in individuals. Light exposure has also been shown to reduce symptoms of depression.
Access to appropriate levels of light in indoor environments can be achieved through building design, space layout and lighting design. Windows, atriums and skylights are design features that can be utilized to increase daylight in a space. The interior layout of the space also has an impact on the daylight exposure received by users; for example, conference rooms can be added to the center of the floor plate so that regularly occupied spaces have daylight exposure. Lighting strategies using electric lighting can be utilized to achieve required light exposure.
Ensure Indoor Light Exposure
For All Spaces except Dwelling Units
Choose between the following:
For Dwelling Units
One of the following requirements is met in each dwelling unit:
Spatial Daylight Autonomy of sDA200/40% is achieved for at least 30% of the space.
Transparent envelope glazing area is no less than 7% of the floor area. Visible light transmittance (VLT) of envelope glazing is greater than 40%.
The following requirement is met:
- Achieve Feature L03: Circadian Lighting Design.
30% of area is within 6 m [20 ft] of transparent envelope glazing. Visible light transmittance (VLT) of transparent glazing is greater than 40%.
Promote Lighting Education
Projects provide educational resources on circadian rhythm, sleep hygiene, age-related increases in light requirements and/or importance of daylight exposure on circadian and mental health that meet at least two of the following requirements:
Educational signage is placed at high traffic points around the space.
Newsletters or newsletter entries are issued to all occupants at least every quarter.
At least two of the resources provided for Part 2: Health and Wellness Education of Feature C01: Health and Wellness Awareness cover information on circadian rhythm, sleep hygiene, age-related increase in light requirements and/or importance of daylight exposure to circadian and mental health.
Note: Education must be culturally appropriate and literacy level appropriate. Education can come in the form of trainings, brochures, videos, posters, pamphlets, newsletters and/or other written or online information. If the requirements of Part 2: Promote Lighting Education are met through the provision of educational materials then these can be counted toward Part 2: Promote Health and Wellness Education in Feature C01: Health and Wellness Awareness.
Projects should consider primary language(s) spoken by the local population when creating signage.
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