Janesville, WI Outdoor Lighting: Dark Sky Rules (2026)

Article XI of Chapter 42 sets physical-development standards applying, per Section 42-386(a), to vacant land and redevelopment zoned O1, O2, O3, B1, B2, B3, B4, B5, B6 and BT, the city's office and business districts, plus building additions doubling a building's gross floor area. Within that article, Section 42-389 sets exterior lighting standards intended to mitigate glare and light spillover onto surrounding properties, especially near residential uses. Subsection (5)a requires all exterior lighting fixtures to be full cut-off fixtures as defined by the Illuminating Engineering Society of North America, with all lighting designed and fixtures selected to prevent glare; the Site Plan Review Coordinator may waive the cut-off requirement only for security lighting not visible from a residential area or public street.

Subsection (5)d caps average illumination at 20 footcandles for the illuminated surface, unless the Plan Commission approves a higher level as part of a conditional use permit. Subsection (5)h sets maximum fixture mounting heights: 18 feet for parking lots with 100 or fewer stalls, 25 feet for larger lots, 10 feet for building or security lighting, and 18 feet for any other site fixture absent Site Plan Review Coordinator approval otherwise. Subsection (5)i further requires that when a use is not operating, only building-mounted security lighting and up to 25 percent of other outdoor fixtures may stay lit. A lighting plan and photometric plan demonstrating compliance must be submitted with development plans under Subsection (5)l.