King County, WA Outdoor Lighting: Light Trespass & Shielding (2026)
Key Facts
- Property-line cap
- 1 foot-candle maximum
- Applies in
- North Highline design-review zones only
- Parking fixture height
- 15 feet maximum
- Shielding required
- Fully shielded, no direct uplight
- Citation
- King County Code § 21A.09.100
Summary
In unincorporated King County's North Highline design-review area, new commercial and multifamily buildings must aim exterior lights onto the building or adjoining ground, capping illumination at the property line at one foot-candle.
All building lights shall be directed onto the building itself or the ground immediately adjoining the building. Illumination at the property line shall be a maximum of one foot-candle.
E. Parking lot lighting fixtures shall be nonglare and mounted no more than fifteen feet above the ground.
F. All lighting fixtures shall be fully shielded, where a solid barrier at the top of the fixture in which the bulb is located blocks all direct uplight. (Ord. 19881 § 184, 2024: Ord. 19687 § 15, 2023. Formerly K.C.C. 21A.60.070). 21A.09.110 Modulation of facades - accompanying architectural measures - approval of changes - balconies that are part of modulation - designs that are easily identified with particular chain or corporation prohibited - chain or corporation signs.
A. Façades with street frontage on new and substantially improved buildings shall be modulated approximately every forty feet. Modulation shall have a depth between three and ten feet and shall be accompanied by at least three of the following architectural measures:
1. Change in window patterns at each modulation, such as window size, color, and shape;
2. Use of vertical piers or columns;
3. Change in roofline or roof style, such as stepped roofs, dormers, gables, or shed roofs, with a vertical modulation of at least twelve inches;
4. Change in color and building material or siding style at each modulation;
Full Breakdown
King County Code § 21A.09.100 sets the lighting standard for North Highline urban design review, which applies to new buildings and substantial improvements in the CB, NB, RB, O, R-12, R-18, R-24 and R-48 zones of the North Highline community service area, plus exterior remodels in the White Center unincorporated activity center. Building lights must aim at the building or the ground right next to it, illumination at the property line caps at one foot-candle, and parking-lot fixtures must be nonglare, fully shielded, and no taller than 15 feet. Outside that specific area, unincorporated King County has no equivalent numeric light-trespass cap, and the rule doesn't reach Seattle, Burien or other nearby cities, which set their own lighting codes.
Violations & Fines
King County DPER (Permitting Division) enforces via code compliance citations under K.C.C. Title 23; a first violation runs $100, escalating to $500 or more for repeat offenses, plus possible stop-work orders.
Frequently Asked Questions
Does this light-trespass rule cover all of unincorporated King County?
Does King County's rule apply inside Seattle?
Sources & Official References
Other rules in King County
Compare King County to another location·View the Washington outdoor lighting overview
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