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

Zoning Ordinance § 2.12(C) sets Dearborn's light-trespass rule as a numeric lot-line limit paired with a fixture-aiming requirement. Subsection C.1, Type, requires all site lighting, whether free-standing, canopy, pole, building-mounted, window-mounted, or landscape, to be "fully shielded and directed downward to prevent off-site glare and illumination." Subsection C.2, Intensity, backs that with hard numbers: light within a site cannot exceed 10 foot-candles anywhere on the lot, and cannot exceed 1.5 foot-candles measured at any lot line. Where the site abuts or faces a residential zoning district or residential use, that lot-line ceiling drops to just 0.5 foot-candles, though approved outdoor sales areas and fuel-station canopy areas may run up to 20 foot-candles internally as long as they still meet the lot-line limits.

A uniformity ratio in C.3 caps the swing between the brightest and dimmest points on a lot at 15-to-1 so a site cannot mask trespass with uneven hot spots. The trespass concept carries into architectural lighting under subsection D: fixtures illuminating a building facade must be "carefully located, aimed and shielded so that light is directed only onto the building facade," and may not be directed toward adjacent streets or properties, with the text stating flatly that "light shall not trespass onto surrounding properties." Before installation, subsection B requires a lighting plan and, where site plan review applies, a photometric plan measuring illumination on a 25-foot grid that projects 25 feet onto adjacent properties or to the setback line, whichever is greater, so trespass is checked with real photometric data rather than a visual estimate.