Idaho Falls, ID Outdoor Lighting: Light Trespass (2026)

Light trespass, when light from one property spills onto a neighboring property, is addressed in Idaho Falls through the exterior lighting standards in the Title 11 Comprehensive Zoning code rather than a dedicated nuisance lighting chapter. The core requirement is that all exterior illumination be shielded and directed downward so as not to produce direct glare on adjacent properties. This shielding-and-aiming standard is the city's main tool against light spilling across property lines. For commercial uses adjacent to residential property, the code adds a measurable cap: no commercial use may cause a level of illumination exceeding one-half (0.5) foot-candle on any part of a contiguous residential area. The code also directs that facilities involving lights be sited, and the lights designed and located, so that glare is minimized. Together these rules give the city a basis to require correction when a neighbor's floodlight, security light, or commercial fixture throws direct glare or excessive light onto an adjoining home. Residents experiencing light trespass should document the source and direction of the light and contact Community Development Services, which administers the zoning code, to evaluate whether the offending fixture is unshielded, improperly aimed, or exceeding the foot-candle limit. Because dark-sky advocates have proposed additional limits, confirm current standards with the city.