Dearborn Heights, MI Outdoor Lighting: Light Trespass & Shielding (2026)

Article XII of the zoning ordinance governs exterior lighting and applies to every outdoor light source visible from a street right-of-way or a residential lot under § 36-441(b). Section 36-441(c) defines light trespass as light falling where it is not wanted or needed, also called spill light, and § 36-442(b) requires fixtures to be focused downward and fully shielded to prevent glare, sky glow, and light trespass onto adjoining properties, mandating full cut-off fixtures so no light projects above a ninety-degree horizontal plane. The numeric standard in § 36-442(d) then sets the enforceable ceiling: light trespass from a property cannot exceed 0.5 foot-candles measured at the property line, five feet above the ground.

The same section requires non-essential lighting, meaning lighting not needed for safety or security, to be shut off after business hours under § 36-442(c), with any proposed security lighting identified on the site plan, and it limits uplighting of buildings for aesthetic effect to the target surface to prevent sky glow under § 36-442(e). Canopy-mounted fixtures must be recessed flush with the canopy ceiling and capped at forty lumens per square foot of canopy under § 36-442(f). These lighting standards are reviewed as part of site plan approval for new construction, additions, and nonresidential development, and the Building and Engineering Department can require a lighting plan showing fixture type, orientation, and photometric coverage before a permit issues.