Outdoor Lighting in Boulder, CO (2026)
2 verified outdoor lighting rules for Boulder, Colorado, sourced directly from the municipal code and official government pages.
Verified from official government sources
Dark Sky Rules
Boulder's outdoor lighting code, Section 9-9-16, exists partly to keep the Milky Way visible from the city's dark sky, and it backs that purpose with hard shielding rules: most bulbs under nine hundred lumens in residential zones must sit in a fully shielded fixture, upward-aimed facade lighting is capped at nine hundred lumens, and every fixture installed after November 15, 2018 must use a warmer, lower color temperature.
Boulder Dark-Sky Outdoor Lighting Shielding Rules
Some RestrictionsBoulder Municipal Code § 9-9-16(a)(4), (d)(5)(B)
Provide an environmentally sensitive nighttime environment that includes the ability to view the stars against a dark sky so that people can see the Milky Way Galaxy from residential and other appropriate viewing areas...(5)Unshielded Lighting:...(B)All lamps and bulbs less than nine hundred lumens located in residential zones shall be within a fully shielded fixture, or must be within a light ...
Light Trespass & Shielding
Boulder caps how much light can spill onto a neighbor's property: Section 9-9-16(d)(1) sets a ceiling of 0.1 footcandles at any point on a property line next to a residential zone, or 0.2 footcandles in nonresidential zones. Fixtures within ten feet of a residential lot line must also be aimed away from it and shielded on the side facing the boundary.
Boulder Light Trespass Property-Line Limits
Some RestrictionsBoulder Municipal Code § 9-9-16(d)(1), (d)(7)
(1)Maximum Light Levels at Property Line: The maximum light level at any point on a property line shall not exceed 0.1 footcandles within or adjacent to a residential zone or 0.2 footcandles in nonresidential zones except as follows...(7)Standards for Lights Adjacent to Residential Zoning Districts, Residential Uses, or Public Rights of Way: Any light fixture located within ten feet of a proper...
Looking for Boulder County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Boulder city rules.
Outdoor Lighting in Boulder County →