What the WELL Community Standard Says About Outdoor Light

Greg Yeutter
Improper application of outdoor lighting can impact healthy and safety. Photo by Sandro Katalina on Unsplash.

There is a small but vocal group of individuals in the lighting community concerned with the state of outdoor lighting. Municipalities are rapidly adopting LED street lighting, hoping to reduce energy and maintenance costs. Yet, these new lighting installations present hazards to human health and safety—not to mention ecological systems—with alarming frequency.

What’s the problem? There are multiple:

  1. Without proper diffusion, LEDs can cause dangerous glare.
  2. Most white LEDs emit significant blue light, which can interrupt human circadian rhythms and ecological patterns.
  3. These bright white sources make the night skies brighter — either through improper shielding or reflection — worsening the effects of #2.
  4. Improper outdoor lighting design can impair visual acuity, leading to dangerous situations.

No wonder those individuals are so concerned.

Who to Blame

It’s hard to blame municipalities for the damage that’s been done. Lighting has gotten so complex in the past few years that trained professionals are required to properly plan and execute lighting installations. It’s certainly not the job of a city government to understand lighting.

Low-glare, Dark Sky compliant lighting? Never heard of it.

But when local and state governments call on lighting specialists for an upgrade, most professionals are not even aware of the problems with outdoor light. They give the customer what they want: a low-energy, low-maintenance lighting installation. Low-glare, Dark Sky compliant lighting? Never heard of it.

The WELL Community Standard

By now, you‘ve probably heard of the WELL Building Standard, a rapidly-growing certification system for healthy buildings. IWBI, the group behind the WELL Building Standard, is expanding its health and wellness focus beyond buildings.

The WELL Community Standard has a lot to say about outdoor lighting.

The WELL Community Standard is a new pilot program focused on healthy communities, with multiple developments already in progress. And—surprise!—it has a lot to say about outdoor lighting.

Light Pollution

The WELL Community Standard defines light pollution as “excessive, misdirected, or obstructed electric light at night that interferes with starlight in the form of reflection, glare, or trespass.” Nighttime lighting in excess has been shown to harm both humans and animals.

The WELL Community Standard seeks to maximize compatibility with other codes and standards.

Clearly, human and animal health is not the only consideration when planning outdoor lighting. Safety, crime reduction, purpose of the space, codes, and aesthetics also inform design choices. Thankfully, the WELL Community Standard seeks to maximize compatibility with other codes and standards while reducing the harmful effects of outdoor lighting.


The following are some specific considerations for outdoor lighting adhering to the WELL Community Standard:

  • Maximum allowable Correlated Color Temperature (CCT)
  • Minimum allowable Color Rendering Index (CRI)
  • Time-controlled dimming or switching off of luminaires
  • Limits to the initial luminous flux (lumens) of luminaires
  • Upward luminaire shielding
  • Prevention of light trespass into residential windows
  • Downlighting, dimming, and luminance limits on signage
  • Uniformity along roadways and pedestrian paths
  • Illumination requirements for crosswalks
  • Glare minimization on roadways, pedestrian paths, and bicycle paths

Are those concerned individuals going to agree with all the recommendations in the WELL Community Standard? Most likely not. But given the list above, it is clear that the new standard is much more than a step in the right direction.

Toward Wider Adoption

The WELL Building Standard doesn’t have the reach of LEED, but consider that it has only been around since late 2014. Most of the buildings that were in the planning stages then are only now starting to see completion. And hundreds of millions of square feet is not nothing.

Likewise, the WELL Community Standard is in the pilot stage right now, and there are only a handful of developments participating in the pilot. It will probably be some time before we see WELL Community Standard certified developments in real life.

In the meantime, municipalities and lighting professionals should take a close look at the lighting recommendations of the WELL Community Standard. They are all on point, whether or not a project is looking for certification.

I am very passionate about the human-centric lighting space and the boost provided by WELL.

I help companies create healthy lighting products. If you are considering strategy or product development in the human-centric space, visit my website greg.lighting or get in touch directly.

Greg Yeutter

Written by

Founder of Bedtime Bulb: https://bedtimebulb.com. Other stuff: https://gregyeutter.com.

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