Dayton adopts exterior‑lighting rules to limit light trespass; holiday and flag exemptions included

The City Council adopted an amendment to Dayton’s zoning code to regulate exterior lighting, aiming to reduce light trespass and support the city’s dark‑sky goals.

Planning staff said the ordinance requires luminaires to be downcast with a cutoff not to exceed 90 degrees, limits lighting at single‑family property lines to 0.5 foot‑candles, and sets a 1.0 foot‑candle limit for commercial, multifamily and institutional properties (with a tighter 0.1 foot‑candle standard where those uses border single‑family lots). The planning commission recommended several adjustments, and council agreed to include an explicit exemption to permit lighting for the American flag and limited holiday displays while maintaining property‑line measurement limits.

Council discussion focused on enforceability, the definition of “holiday” or “temporary” displays, low‑level landscaping lights and whether color temperature (Kelvin) should be regulated. Some members favored stricter cutoffs; others warned about practical enforcement and measurement tools. The council amended the staff draft to clarify exempted flag lighting and to avoid prohibiting small, downcast landscape fixtures; the motion to adopt passed with one abstention.

The ordinance establishes a photometric standard to be reviewed as part of permitting for new developments; staff said phone‑based light meters and photometric plans will be used for enforcement and that temporary holiday lighting remains subject to the property‑line foot‑candle limits.

What happens next: staff will incorporate the final language into the ordinance text, make the flag‑lighting clarification explicit, and implement the ordinance through building permit and code‑enforcement processes.