Stanislaus County, CA Outdoor Lighting: Light Trespass (2026)

Light trespass (light spilling onto neighboring property) is not addressed by a single residential ordinance in unincorporated Stanislaus County, but several Title 21 provisions limit it. The clearest standard appears in the industrial and business-park performance standards: Sections 21.61.110 (Industrial Business Park) and 21.62.110 (Light Industrial), along with parallel language for other industrial (M) and limited-industrial districts, require that 'no direct or sky-reflected glare or heat... shall be visible or felt at the property line.' That is effectively a zero-trespass rule at the boundary for those uses. For discretionary and special uses, the ordinance commonly conditions approval on lighting that 'shall be shielded and reflected away from adjacent uses,' directing illumination down and inward. For residential parcels where no performance-standard district applies, the principal control is the general nuisance provision, Section 21.08.100, which states that 'no use shall be conducted on any premises in such a manner as to cause an unreasonable amount of noise, odor, dust, smoke, vibration, electrical interference, or other nuisance condition detectable off the site.' Excessive light intrusion onto a neighbor's property can fall within that prohibition. Because there is no numeric foot-candle limit in the code, light-trespass disputes between neighbors are generally handled through the nuisance standard and code enforcement rather than a specific lighting metric. Owners experiencing or causing light trespass should contact Code Enforcement or the Planning Department.