Caldwell, ID Outdoor Lighting: Light Trespass (2026)

Caldwell limits light trespass - light from one property spilling onto another - through its Standards for Outdoor Lighting in City Code 10-08-09. The shielding requirements directly reduce spillover: fixtures over 15 feet in height must use a full cutoff shield so light is directed downward rather than across property lines, and uplighting is permitted only where the fixture and its light are shielded from the sky by a roof overhang or similar structural shield. Floodlights, a common source of neighbor complaints, must be sensor-activated and must switch off within 5 minutes after activity on the property ceases, preventing all-night glare into adjacent windows and yards; floodlights are also prohibited downtown except in alleys. Secondary reporting on Caldwell's standards describes a light-trespass limit on the order of 0.1 foot-candle measured across property lines, consistent with the code's shielding intent, though property owners should confirm the exact numeric threshold against the current text of 10-08-09. Practically, a homeowner whose neighbor's security light shines into their bedroom can point to these shielding and motion-sensor requirements when asking the city's Code Compliance Division to enforce. Choosing full-cutoff, downward-directed fixtures and aiming lights onto your own property is the simplest way to stay compliant.