Boise, ID Outdoor Lighting: Dark Sky Rules (2026)
Key Facts
- Fixture type required
- Full cutoff, fully shielded
- Light trespass cap
- 1.0 footcandle at property line
- Color temperature limit
- 3,500K max
- Curfew (most districts)
- Off 11 PM to sunrise
- Banned sources
- Searchlights, lasers, mercury vapor
Summary
Boise requires fully shielded, full-cutoff outdoor light fixtures citywide to cut glare, sky-glow, and light spilling onto neighbors.
B. Shielding: (1) All lighting fixtures, except motion detector-activated lighting, shall be fully shielded so that the lighting element is not visible to an observer at any property line. (2) Unless otherwise specified, all lighting fixtures shall be full cutoff type as installed... C. Light Trespass: All lighting shall be designed so that the lighting level at each property line that does not front on a public or private street shall not exceed 1.0 footcandle.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: 2026 S-31: Code current through: Ord. 20-26, passed 6-9-2026).
Full Breakdown
Boise City Code § 11-04-011 requires nearly all exterior lighting fixtures to be fully shielded and full-cutoff so the light source isn't visible from the property line, caps light trespass at 1.0 footcandle at non-street-facing property lines, limits color temperature to 3,500K, and requires most residential, mixed-use, industrial, and open-land district fixtures to shut off between 11:00 p.m. and sunrise except for security or walkway lighting. Searchlights, lasers, strobes, mercury vapor, and low-pressure sodium lighting are banned outright.
Violations & Fines
Enforced through the zoning certificate, design review, or conditional use permit process administered by the Planning Director; noncompliant lighting can hold up permit approval or trigger a code enforcement case requiring retrofit to a shielded, full-cutoff fixture.
Frequently Asked Questions
Does Boise require dark-sky-compliant lighting?
How much light can cross onto a neighbor's property in Boise?
Sources & Official References
Other rules in Boise
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