Littleton, CO Outdoor Lighting: Dark Sky Rules (2026)

The Outdoor Lighting Standards section states its purpose is to regulate light trespass and glare to protect motorists and pedestrians and to keep lighting from adversely affecting adjacent land uses, including minimizing light pollution while promoting energy-efficient, cost-effective lighting. That purpose is carried out through the shielding standard: all exterior luminaires must be full cutoff fixtures directed downward, and in no case may lighting be aimed above a horizontal plane through the fixture, or more than 45 degrees from the surface the fixture is mounted on, when the light source is visible from an off-site residential property or public roadway.

This shielding rule works together with the code's fixture-type standard, which requires exterior fixtures to direct light downward and inward toward the site, and caps building-mounted fixtures at the height of the first-story eave or 14 feet above grade, whichever is lower. Pole-mounted lighting height is separately capped at 30 feet above grade generally, or 25 feet for properties in or adjacent to a residential district, dropping to 18 feet in the Downtown district. The code also flatly prohibits several fixture types outright: laser or similarly high-intensity lights projected above horizontal, flashing or intermittent fixtures, unshielded wall packs, and privately owned fixtures located in the public right-of-way.

These shielding and prohibited-lighting rules apply to new development, to redevelopment expanding a facility's intensity or floor area by 25 percent or more, and to new and existing single-family residential lighting alike.