Outdoor Lighting in Washington County, OR (2026)
3 county-level rules, plus city-specific rules for 2 cities in Washington County, Oregon.
Verified from official government sources
Dark Sky Rules
Exterior lighting on new attached-unit and non-residential developments in unincorporated Washington County must meet cutoff standards tied to fixture height. Section 415-4 lets a shielded, cutoff-type luminaire climb to 40 feet in commercial and industrial districts, while unshielded fixtures are capped at 10 to 20 feet under lower brightness limits.
Washington County Cutoff Lighting Fixture Rule
Some RestrictionsWashington County Community Development Code § 415-4
415-4Standards The following standards are required of all exterior lighting except the outdoor recreational uses specifically exempted below. ... 415-4.3When a luminaire has total cutoff of light at an angle less than 90 degrees (Figure 1) and is located so that the bare light bulb, lamp, or light source is completely shielded from the direct view of an observer 5 feet above the ground at the ...
Light Trespass & Shielding
Washington County measures light trespass at the property line, not at the fixture. Section 415-3.8 defines maximum permitted illumination as the foot-candle level at the property line or required buffer, and Section 415-5.3 separately bars lighting from shining excessive light into nearby habitat areas.
Washington County Light Trespass Limits
Some RestrictionsWashington County Community Development Code §§ 415-3.8, 415-5
415-3.8Maximum permitted illumination: The maximum illumination measured in foot-candles at the property line or, if required, interior screening and buffering line at ground level, in accordance with the standards of Section 415-4 below. ... 415-5General Provisions Notwithstanding any other provision of this Section to the contrary: 415-5.1No flickering or flashing lights shall be permitted.41...
Billboard Lighting
Digital billboards permitted in Washington County's General Commercial District can only show static, unmoving messages and must cap brightness at 0.3 foot-candles over ambient light measured 150 feet away. Section 414-7.4 also requires an automatic light sensor and a fail-safe that freezes, blacks out or shuts off the display on malfunction.
Washington County Digital Billboard Lighting Rule
Some RestrictionsWashington County Community Development Code § 414-7.4
414-7.4Digital billboards allowed pursuant to Section 414-2.2 G shall:A.Display only static messages that remain constant in illumination intensity and do not have movement or the appearance or optical illusion of movement;B.Not operate at an intensity level of more than 0.3 foot-candles over ambient light as measured at a distance of 150 feet;C.Be equipped with a light sensor that automaticall...
Outdoor Lighting by City in Washington County
2 cities in Washington County have their own outdoor lighting rules. Each link goes to that city's dedicated page with code citations.
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