Santa Clara County, CA Outdoor Lighting: Light Trespass (2026)

County Code Division C12 limits horizontal and vertical illuminance at residential property lines to a maximum of 0.5 footcandles when measured 5 feet above grade, based on California Building Energy Efficiency Standards Title 24 Part 6 outdoor lighting chapter. Exterior fixtures must be full-cutoff, meaning no light is emitted above the horizontal plane through the fixture. Floodlights, security lights, and landscape fixtures may not be aimed toward residential windows on neighboring lots. Decorative sconces under 700 lumens are exempt. Commercial properties abutting residential zones must reduce lighting to dimmed night levels after business hours. Tenants and owners can file complaints with the Santa Clara County Planning Department Code Enforcement at 408 299 5700, and the department can inspect and issue a notice of violation with 30 days to cure. Unresolved light trespass is also a private nuisance under Civil Code 3479 and can be enforced by injunction in Santa Clara County Superior Court with damages for loss of enjoyment. HOAs typically have overlapping rules, and architectural review under Civil Code 4765 can address light spillover between units. Holiday and special-event lighting is exempt from the 0.5 footcandle cap for limited periods.