Rancho Cucamonga, CA Outdoor Lighting: Light Trespass (2026)

Light trespass, the spillover of outdoor lighting onto neighboring properties, is regulated in Rancho Cucamonga through Development Code Section 17.58 and general nuisance provisions in Municipal Code Title 8. The specific standard limits illumination at any residential property line to 0.5 foot-candles (measured 5 feet above grade), and at non-residential property lines to 1.0 foot-candles. New commercial, industrial, and multi-family developments must submit photometric site plans during plan check to demonstrate compliance. Existing installations that create trespass typically must be retrofit with shielding, aimed downward, or reduced in wattage following a complaint investigation. Common violations include poorly aimed security floodlights, unshielded garage wall-packs, and over-bright landscape lighting affecting adjacent bedrooms. Complaints can be filed with the Planning Department or Code Enforcement, which conducts nighttime measurements and can issue notices to abate. Remedies range from simple fixture adjustment to full replacement with compliant fixtures. Persistent violations may be cited as public nuisances under California Civil Code Section 3479.