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

Santa Clara County controls light trespass (light crossing onto neighboring property) through performance standards embedded in the Zoning Ordinance rather than through a single numeric residential cap. For home occupations, Section 4.10.040 prohibits any activity that creates offensive glare or radio/television interference that is noticeable from beyond the property boundaries, and the same no-off-site-nuisance standard appears in other residential and accessory-use provisions. For light poles associated with certain structures, the ordinance requires fixtures to be shielded so the light source is not visible from beyond the boundaries of the subject property. Nonresidential off-street parking lighting under Section 4.30.070 must be designed to confine direct rays to the premises, with any spillover beyond the property line (except onto public thoroughfares) subject to approval by the approving authority, and any spillover onto public thoroughfares must not create a hazard to motorists. Emergency-shelter and similar use standards require that lighting not be directed toward adjacent properties or public rights-of-way. Where lighting causes a recurring off-site impact, the County also has general nuisance authority. Because there is no fixed maximum illuminance at the property line for ordinary residential fixtures, complaints are evaluated against these performance and shielding standards and the conditions of any applicable land-use approval.