Night Sky
Fort Collins supports a Night Sky Initiative promoting outdoor lighting best practices that reduce light pollution while maintaining safety. Learn about regulations, retrofitting requirements and lighting principles that protect our night sky.
Overview
Seeing the stars at night and using best practices in outdoor lighting work together. As Fort Collins grows, there will be more commercial and residential outdoor lighting.
The City supports a Night Sky Initiative of outdoor lighting best practices that eliminate light glare, reduce light trespass, minimize light pollution, conserve energy and protect the natural environment. This effort supports safety, energy conservation, a healthy ecosystem and innovation.
The City seeks to maintain safety and security, develop and implement best practices in outdoor lighting, reduce light pollution, and support human and ecological health.
What Is Light Pollution?
Light pollution happens when cities grow and need more outdoor lighting. While outdoor lighting is important in many situations, using too much or the wrong kind has negative effects.
Common terms associated with light pollution include glare (too much brightness that causes visual discomfort), skyglow (brightening of the night sky over inhabited areas), light trespass (light falling where it is not intended or needed), and clutter (bright, confusing and excessive groupings of light sources).Preventing light pollution results in energy and cost savings as well as better lighting of the things we need to see at night.
Best Practice Principles
Anytime you're installing or replacing a light fixture consider these principles:
- Light only where you need it
- Light only when you need it
- Shield and recess lights and direct them downward
- Use the minimum amount of light needed
- Select energy efficient lighting
- Select lamps with warmer colors
Why Is Color Important?
Light can have subtle and not so subtle impacts on humans and wildlife. Selecting an appropriate color temperature for lighting needs is important. During high daylight hours (7 a.m.-3 p.m.) whiter light matches the natural sunlight in the outdoor environment. Similarly, during non-daylight hours (4 p.m.-6 a.m.) warmer colors will better match the natural environment and won't be as wakeful and stimulating to human and animal brains.
More is being learned about blue light and studies show that blue light in dusk through evening hours can have negative effects on humans and wildlife.
How Bright Are We?
Fort Collins average light pollution values are 20 times brighter than natural conditions. This means that a typical sky in Fort Collins is 20 times brighter than that of a sky with no light pollution. The lowest levels are 7.5 times brighter than natural and the maximum is around 35 times brighter.
Within natural areas and open spaces the average night sky is 4 times brighter than natural conditions. The darkest skies found in Soapstone Natural Area are just 1.1 times darker than natural conditions and offer outstanding views of the cosmos.
Local Regulations on Exterior Lighting
City of Fort Collins regulates exterior lighting through different codes. The Land Use Code regulates new or changes to existing multi-family and commercial developments. For more information, see Division 5.12 of the Land Use Code.
Building Codes also address outdoor lighting for both commercial and residential uses by requiring down directional and fully shielded luminaires with a nominal color temperature of no greater than 3000 Kelvin. All fixtures must comply with these requirements. For more information see the Building Code.
Planning a Retrofit? If you are planning a retrofit, keep in mind all codes require fully shielded fixtures. Additionally, if your retrofit is a commercial or multi-family development, your project will likely need to undergo (at minimum) the Minor Amendment Process for approval.