Dark Sky Rules: Concord vs San Ramon

Concord does not have a formal dark-sky ordinance but CMC Title 18 requires exterior lighting to be shielded, downcast, and not spill onto neighboring properties. New development must submit a photometric plan demonstrating zero foot-candle spillover at property lines.

San Ramon regulates outdoor lighting through its Development Code (Title D) to reduce light pollution, glare, and spillover onto adjacent properties. Requirements include shielded fixtures, downward-directed light, and limits on lumens and color temperature (typically 3000K or below preferred). The city is not a formal IDA Dark Sky community but incorporates dark-sky principles in design review for new development, especially near open space preserves (Bishop Ranch Regional Preserve, Las Trampas).