Longmont, CO Outdoor Lighting: Light Trespass & Shielding (2026)
Key Facts
- Trespass limit
- 0.1 footcandles at residential property line
- Applies to
- Residential use, greenway, natural area
- Fixtures must be
- Concealed or shielded, § 15.05.140.G.3
- Aim rule
- No light directed at property boundaries
- Off-hours rule
- Unneeded security lights sensored or off
- Rec-field cap
- 2.0 footcandles at property line
Summary
Longmont caps how much light can spill onto a neighboring residential lot, greenway or natural area at 0.1 footcandles at the property line under Municipal Code § 15.05.140.G.7. Fixture owners must also conceal or shield light sources to limit glare (G.3) and cut unnecessary security lighting after hours or motion-activate it (G.9).
3.Light sources shall be concealed or shielded to minimize the potential for glare and light pollution.4.Light fixtures shall be installed so that the luminaire angle is zero degrees (vertical to the ground).5.No light sources shall be directed toward property boundaries or adjacent rights-of-way.6.Lights, such as wallpacks, that shine outward and create direct glare are prohibited.7.The amount of nuisance glare (light trespass) projected onto a residential use, greenway or natural area from another property shall not exceed 0.1 footcandles at the property line.8.Lighting shall be distributed evenly to minimize extremes in luminance levels.9.Light fixtures not necessary for security purposes shall be reduced, activated by motion sensor devices, or turned off during hours when the business or use is not open.
Full Breakdown
4). ' Getting there is a design obligation, not just an outcome to hit after the fact. 5 bars aiming any light source toward a property boundary or adjacent right-of-way. 1 footcandles. 4). b.
Violations & Fines
A light trespass complaint that shows more than 0.1 footcandles at a residential property line, or a fixture aimed at a neighboring lot, is a development-code violation under § 15.09.030. The director can order the fixture modified after installation under § 15.05.140.F.4, and under § 15.09.050 the city can withhold or deny building permits and certificates of occupancy, revoke an issued permit, or seek an injunction until the glare is corrected.
Frequently Asked Questions
How is light trespass measured?
Can my neighbor point a floodlight at my yard?
Does a security light have to stay off all night?
What can I do if a neighboring business's lighting spills onto my property?
Sources & Official References
Other rules in Longmont
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Light Trespass & Shielding in Nearby Cities
How other cities in Boulder County handle light trespass & shielding.