Dark Sky Rules: Renton vs Seattle
How do dark sky rules rules compare between Renton, WA and Seattle, WA?
Renton and Seattle have similar restriction levels.
Renton, WA
King County
Renton Municipal Code 4-4-075 regulates outdoor lighting in commercial and multifamily projects to control glare and light trespass. Full cutoff fixtures are generally required in new non-residential development.
View full Renton rules →Seattle, WA
King County
Seattle Municipal Code regulates outdoor lighting through zoning standards in §23.45 (residential) and §23.47A (commercial). Fully-shielded fixtures are required on new commercial installations, light trespass is capped at 0.5 foot-candles at residential lines, and recent rules cap color temperature at 3000K. Seattle works with King County on regional dark-sky alignment.
View full Seattle rules →Key Facts Comparison
| Fact | Renton | Seattle |
|---|---|---|
| Code reference | RMC 4-4-075 | - |
| Cutoff required | Non-residential and multifamily | - |
| Pole height limit | Typically 20 to 25 feet | - |
| Trespass limit | About 0.5 foot-candles at residential property line | - |
| Single-family | Largely unregulated except nuisance | - |
| - | - |
Highlighted rows indicate differences between cities.
Renton FAQ
Do residential porch lights need to be dark-sky compliant?
Single-family residential lighting is largely unregulated unless it becomes a nuisance to neighbors. Shielded fixtures are encouraged but not mandated.
What qualifies as a full cutoff fixture?
A fixture that emits zero light above the horizontal plane of the lamp, directing all output downward, as defined by IES TM-15.
Seattle FAQ
Do I need to replace existing fixtures?
No. Pre-existing fixtures are grandfathered. New installations, replacements, and major remodels must comply with current SMC standards.
Are holiday lights exempt?
Yes. Seasonal decorative lighting is exempt November 15 to January 15 provided fixtures aren't aimed at the sky or laser-projected.
What color temperature is allowed?
New outdoor LEDs are capped at 3000K under the 2022 amendment. Warm-white 2700K is encouraged for residential.
Compare other topics
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