Gaithersburg, MD Outdoor Lighting: Dark Sky Rules (2026)

2 of the zoning code applies to the replacement and installation of all new lighting fixtures tied to any building or use, with exceptions carved out for FAA-regulated lighting, emergency lighting used by police, fire, or medical personnel, code-required exit and stair lighting that cannot otherwise comply, underwater pool and fountain lighting, and temporary holiday lighting. Under subsection (D), lasers, searchlights, strobe lights, and blinking lights are prohibited outright, as are low-pressure sodium, mercury vapor, or other lighting the director of public works determines is not energy efficient.

Subsection (E) then sets the shielding standard itself: exterior lighting must use full cut-off or directionally shielded fixtures, aimed and controlled so the directed light stays substantially confined to the object being illuminated and does not cross the property boundary. Only incandescent, LED, fluorescent, metal halide, or color-corrected high-pressure sodium sources may be used, and the same light source type must be used for similar fixtures across any one development. Any lighting on a property abutting land zoned or developed for single-family homes must carry supplemental opaque shielding on the residential side of the fixture to cut glare.

Lighting fixtures lawfully installed before the section took effect and that do not meet these standards are treated as legally nonconforming and may stay in place. 5 foot-candles across the lit surface, and sit between 12 and 14 feet high on a pole, wall, or structure, with bollard lamps capped at 4 feet.