Alameda, CA Outdoor Lighting: Light Trespass (2026)

Alameda addresses light trespass directly in its Dark Skies ordinance, AMC Section 30-5.16. The Light Trespass standard states that exterior lighting shall be directed downward and away from property lines to prevent excessive glare beyond the subject property, and that no light, combination of lights, or activity shall cast light exceeding one (1) foot-candle onto an adjacent or nearby property - with the illumination level measured at the property line between the lot on which the light is located and the adjacent lot, at the point nearest to the light source. The code defines 'light trespass' as light emitted by a luminaire that shines beyond the property on which the light is located, and a 'foot-candle' as the standard unit for the intensity of light falling on a surface. Supporting standards reinforce this limit: all exterior fixtures must be fully shielded and directed downward; security lighting must use shielded, downward fixtures (floodlights are not permitted) and higher-output security lights (100+ watts or 1,600+ lumens) must be on motion sensors; and vertical building features may be illuminated for security only up to 8 feet above grade. A separate performance standard (AMC 30-5.16(f)) also prohibits any heat or direct/sky-reflected glare visible or discernible from a property line. These provisions give neighbors a concrete, measurable standard - 1 foot-candle at the shared property line - for complaints about spillover light.