This is a legacy version of the WELL Building Standard. Please check the latest version here.
   
  1. Light
  2. Light at night

Light at night

Features/Light/Feature P2

Light at night

Intent: 

To provide sleeping spaces free from light intrusion and provide low-light wayfinding options.

P2: Light at night

    BACKGROUND

    Light is the primary zeitgeber, the signal by which the body aligns its internal clock with the external environment. Therefore light at night is a potential hazard as it can disrupt circadian rhythm. It blurs the distinction between day and night, and affects the timing of the sleep-wake cycle. However, complete darkness increases the sensitivity of the eyes, so any lights encountered during activities at night have an amplified disruptive effect.

    Part 1
    Window Light Elimination

    All bedroom windows employ one of the following:
    a.
    Blackout shades with 0% transmittance and no light gaps on the perimeter.
    b.
    Operable outdoor shutters with 0% transmittance.

    Part 2
    Electric Light Elimination

    In all bedrooms, the following requirement is met:
    a.
    All electronics have an option to produce no light.

    Part 3
    Safe Nighttime Navigation Lighting

    The following conditions are met:
    a.
    Nightlights are installed to provide a safe path from all sleeping areas to the closest bathroom and within the bathroom.
    b.
    Nightlights are located no higher off the ground than 36 cm [14 inches] to the center of the unit.
    c.
    Nightlights are motion-activated with a manual off and manual on option.
    d.
    Nightlights do not emit light at wavelengths below 550 nm.
    e.
    Each nightlight does not produce more than 15 lumens.