Ada County, ID Outdoor Lighting: Dark Sky Rules (2026)
Key Facts
- Opaque top over
- 260 lumens
- Full cut-off shield over
- 1,800 lumens
- Prohibited
- Mercury vapor, skyward lasers
- Up-lighting
- Only if shielded from sky
- Code section
- Ada County 8-3-8
Summary
Ada County's outdoor-lighting standards regulate glare and up-lighting to protect nighttime skies. Fixtures over 260 lumens must have an opaque top to prevent up-lighting; fixtures at 1,800 lumens or more require a full cut-off shield. Mercury-vapor lamps and skyward lasers are prohibited.
One Thousand Eight Hundred (1,800) Lumens or More. Light fixtures that have a maximum output of one thousand eight hundred (1,800) lumens or more shall have a 'full cut off shield.'
Full Breakdown
Ada County Code Section 8-3-8 sets outdoor-lighting standards for unincorporated development to conserve energy, regulate glare, prevent nuisance, and enhance nighttime enjoyment. Fixtures under 260 lumens are exempt. Fixtures of 260 lumens or more must have an opaque top to prevent up-lighting; at 1,000 lumens the bulb must not be visible; and at 1,800 lumens or more a 'full cut off shield' is required. Up-lighting is allowed only where shielded from the sky by a roof overhang or similar shield. Mercury-vapor lamps, skyward lasers, and advertising searchlights are prohibited, and rural base districts prohibit neon illumination. These standards apply to unincorporated Ada County; cities set their own lighting rules.
Violations & Fines
Installing prohibited fixtures or unshielded lighting that fails Section 8-3-8 is a zoning violation; Development Services can withhold approval or require compliant fixtures.
Frequently Asked Questions
Does Ada County have dark-sky lighting rules?
Can I aim a light up at a flag or tree?
Sources & Official References
Other rules in Ada County
Compare Ada County to another location·View the Idaho outdoor lighting overview
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