Fort Collins, CO Outdoor Lighting: Light Trespass & Shielding (2026)
Key Facts
- Buffer zone cap
- 0.0 footcandles at lot line
- LC1 residential cap
- 0.1 footcandles
- LC2 commercial cap
- 0.3 footcandles
- LC3 downtown cap
- 0.8 footcandles
- Measurement spacing
- Every 10 feet along lot lines
- Applies to
- Applications filed before May 17, 2024
Summary
Fort Collins capped how much light a development could throw across its own lot line, from zero footcandles into natural habitat buffers up to 0.8 footcandles in the densest downtown lighting zone. Section 3.2.4 of the Transitional Land Use Code set the numbers for applications filed before May 17, 2024.
(4)Demonstrate no light trespass onto Natural Areas, Natural Habitat Buffer Zones or River Landscape Buffers as defined in Section 4.16(E)(5)(b)(1)(a). ... (I)Limits to Off-Site Impacts. ... Light Trespass Limitations. The illuminance levels provided in Table 3.2.4-4 shall be used for enforcement, should concerns of obtrusive lighting or question of compliance arise. Lighting plans shall show horizontal illuminance along all lot lines with calculation points spaced no further than ten (10) feet apart. This provision shall apply to all exterior lighting. Lighting Context Area Maximum Horizontal Illuminance Natural Habitat Buffer Zones and River District Landscape Buffers 0.0
LC0 0.0 LC1 0.1 LC2 0.3 LC3 0.8
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Municipal Code: Supplement 155 | Transitional Land Use Code (for project before May 17, 2024): Supplement 61 | Traffic Code: Supplement 27).
Full Breakdown
8 footcandles. ' For property lines abutting public rights-of-way, private streets, private drives, public alleys, or parking lots, the backlight, glare and illuminance values were instead measured ten feet in from the boundary rather than at the line itself. Luminaires had to be rated under the Section's BUG (Backlight-Uplight-Glare) tables based on mounting height and orientation relative to the property line, with fixtures mounted less than half a mounting height from the line and not ideally oriented held to the strictest ratings.
Violations & Fines
A lighting plan that fails the Section 3.2.4(I) illuminance table is not approved, and installed lighting exceeding the cap after occupancy is a Land Use Code violation under Section 2.14.4(A), treated as a misdemeanor subject to City Code Section 1-15 penalties with each day of noncompliance a separate offense (fines up to $2,650 for an unclassified misdemeanor). The City can require retrofitting of noncompliant fixtures as a condition of any building permit or certificate of occupancy tied to the property.
Frequently Asked Questions
How much light can spill onto my neighbor's property in Fort Collins?
Is any light trespass allowed into natural areas?
Where is illuminance measured for light trespass compliance?
Sources & Official References
Other rules in Fort Collins
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