Contra Costa County, CA Outdoor Lighting: Light Trespass & Shielding (2026)

404(a)(8) of the county's off-street parking design standards targets light trespass and glare from commercial and industrial parking lots. It applies to every parking area in a non-residential zoning district, defined as any zone other than the county's R-, D-1, or M- residential and multiple-family districts, which in practice covers office, commercial, industrial, and planned unit parking lots. The section defines the two harms it targets in its own text: 'glare' is overwhelming direct light creating a potential hazard, and 'light spill-over' is an unreasonable amount of light extending beyond the intended parking area or the property line, both measured as seen from adjacent areas, streets, or rights-of-way.

To prevent either, fixtures must be directed downward and away from neighboring properties and public streets, and the overall intensity cannot exceed what is reasonably needed to safely and securely light the lot, a standard written explicitly to protect the privacy and well being of residential areas bordering a commercial site. The section also folds in an ongoing maintenance duty: burnt-out or broken bulbs must be replaced, fixtures kept clean and free of graffiti and rust, and painted housings kept from chipping or peeling, so a compliant lighting plan approved at permitting does not degrade into a nuisance over time. The zoning administrator reviews lighting plans as part of site plan or land use permit approval for these non-residential parking areas.