Douglas County, CO Outdoor Lighting: Light Trespass & Shielding (2026)
Key Facts
- Spill limit
- 0.1 foot-candles at 20 feet
- Near property line
- Shielding within 15 feet
- Disability glare
- Prohibited on neighbors
- Glare threshold
- Over 2,500 nits
- Governing section
- DCZR 3005.04, 3005.18
Summary
Douglas County's lighting standards limit light spilling onto neighbors. Fixtures within 15 feet of a residential property line must be shielded, and light may not exceed 0.1 foot-candles measured 20 feet from the property line. No fixture may create disability glare on adjacent property.
All light fixtures mounted within 15' of any residential property line of the site shall be classified as IES Type II or Type III ... Light levels shall not exceed 0.1 foot-candles 20' from the abutting property line as a direct result of the on-site lighting.
Full Breakdown
Section 30 defines light trespass as light from an artificial source intruding where it is not wanted. Section 3005.04 requires fixtures mounted within 15 feet of a residential property line to be shielded with house-side reflectors and limits light to 0.1 foot-candles measured 20 feet from the abutting property line. Section 3005.18 bars any fixture, including interior fixtures visible through windows, from creating disability glare on adjacent properties. The definitions section treats glare exceeding 2,500 nits as disability glare. These limits mainly govern commercial and multi-family sites; single-family lighting is largely exempt but still may not cause disability glare.
Violations & Fines
A property owner whose lighting exceeds these limits can be required, through enforcement or site-plan conditions, to shield, re-aim, or replace the offending fixtures.
Frequently Asked Questions
My neighbor's floodlight shines into my yard - is that allowed?
Do these rules cover a bright interior light seen through a window?
Sources & Official References
Other rules in Douglas County
Compare Douglas County to another location·View the Colorado outdoor lighting overview
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