Mountain View, CA Sign Regulations: Window Signs (2026)

Sec. 15(j)(1) governs window signs for commercial uses with ground-floor frontage: a maximum of one window sign is permitted per window pane or framed window area, and it cannot occupy more than 25 percent of the total transparent glass area of the street-facing, ground-floor windows (excluding glass doors), or one square foot per linear foot of occupancy frontage on a public street, whichever produces the smaller sign. Lettering on any window sign is capped at 12 inches in height. Except where neon is allowed, window signs must be nonilluminated or only internally or indirectly illuminated, and must consist of painted or gold-leaf lettering directly on the glass, or plastic, wood, metal, or other high-quality solid material, or a solidly framed poster or sign board.

Neon window signs are permitted within four feet of the window only if all electrical supply cords, conduits, and transformers are hidden from view and all required electrical and building permits are obtained. Second-floor commercial uses get a tighter allowance under Sec. 15(j)(2): one window sign per pane, capped at 15 percent of the second-floor transparent glass area, 12-inch maximum lettering, and nonilluminated painted or gold-leaf construction only. Window signs above the second floor are flatly prohibited under Sec. 15(j)(3). Graphics or displays with lettering over one inch mounted within four feet of a window are treated as regulated window signs too, except for sub-one-inch lettering, retail products on shelves, or information panels that are at least 80 percent small-type text.

Inside the Downtown Precise Plan area, Sec. 80 imposes the same 25 percent/one-square-foot-per-linear-foot ground-floor formula but additionally requires window signs to be professionally designed and limited to gold leaf or painted glass or other zoning-administrator-approved high-quality graphics.