Florissant, MO Outdoor Lighting: Dark Sky Rules (2026)

Chapter 405's lighting standard applies to all new outdoor fixtures and replacements of existing fixtures in the "B-1" through "B-5" business districts, the "M-1" through "M-3" manufacturing districts, and commercial uses located in the "R-4" and "R-6" districts. Single-family and single-family-attached homes are exempt, along with street lighting, monument and landmark lighting, signage covered by Chapter 520, temporary seasonal or emergency lighting, and lighting regulated by the FAA or another federal or state agency. A fixture is "fully shielded" only when it is built and mounted so every bit of light stays below a horizontal plane through the lowest light-emitting point, with none visible above that line.

Parking lots must use flat-lens, fully shielded fixtures; the Planning and Zoning Commission can approve a decorative substitute only if a photometric plan shows off-site glare stays within the code's limits and the fixture fits the surrounding development's character. Pole height is capped at sixteen feet for lighting serving residential uses and twenty-five feet for everything else, rising to thirty-five feet on lots over five acres if the pole sits at least one hundred feet from any residential use and the Commission signs off; anything taller is barred outside outdoor recreational facilities.

Site plans that add or change exterior lighting must include a full lighting plan, prepared by a qualified lighting professional, showing fixture locations, specifications, proposed operating hours and a photometric layout, filed with any development application and reviewed by the Director of Public Works. Replacement fixtures installed before the September 22, 2025 effective date can keep operating as long as less than sixty percent of a property's fixtures have since been swapped and the new unit does not raise the foot-candle level or reduce shielding. No lighting standard, fixture or system may be erected, installed or modified without a building or electrical permit from the Building Official.