Denver County, CO Outdoor Lighting: Dark Sky Rules (2026)

Denver Zoning Code Article 10 and DRMC §59-200 (former Chapter 59 outdoor lighting standards) set outdoor lighting rules. For new commercial, mixed-use, and multifamily developments, lighting must use fully shielded (IESNA 'full cutoff' rated) fixtures directing light downward, with maximum lumen outputs tied to area type. LED correlated color temperature (CCT) must not exceed 3000K in most districts, and 2700K is recommended to reduce blue light spill and align with Denver's Climate Action pollinator goals. Parking lot pole heights and illuminance are capped to prevent spill onto neighboring residential properties (typically ≤0.5 foot-candle at the property line adjacent to residential). Electronic billboards and signs have separate brightness rules. Historic districts impose additional lighting fixture standards through Landmark Preservation. Residential single-family lighting is less prescriptive but subject to nuisance rules — light trespass onto neighboring properties is actionable (see light-trespass entry). Denver does not currently have full International Dark-Sky certification, but its astronomy-community interest has grown; many Front Range communities (Longmont, Westminster) are closer to dark-sky ordinances.