Loudoun County, VA Outdoor Lighting: Dark Sky Rules (2026)
Key Facts
- Fixture standard
- Full cutoff, IDA Fixture Seal of Approval accepted
- Color temperature cap
- 3000K Correlated Color Temperature or less
- Stated goal
- Promote IDA Dark Sky standards, prevent light pollution
- Side shielding
- Required on pole-mounted fixtures (exc. driveways)
- Civil penalty
- $200 first charge, $500 each additional
Summary
Loudoun County's Zoning Ordinance directly adopts International Dark-Sky Association standards for outdoor lighting: full-cutoff fixtures verified by an IDA Fixture Seal of Approval, a 3000K cap on bulb color temperature, and a stated purpose to 'implement General Plan action to promote the International Dark-Sky Association's Dark Sky standards to prevent light pollution.'
Implement General Plan action to promote the International Dark-Sky Association's Dark Sky standards to prevent light pollution. ... a. Lighting fixtures must be full cutoff so that the emitted light is not projected above the horizontal plane of the shield... Verification of this standard for each lighting fixture is required by: 1. Manufacturer certification; or 2. The International Dark Sky Association Fixture Seal of Approval. ... 6. Color Temperature. To minimize negative environmental impacts of outdoor lighting, all new luminaires must be rated 3000K or less Correlated Color Temperature (CCT).
Full Breakdown
' The ordinance operationalizes that goal in its General Standards. a requires every lighting fixture to be full cutoff, light may not project above the horizontal plane of the shield, and the bulb must sit recessed or level with the shield's lowest edge, and compliance can be verified by 'the International Dark Sky Association Fixture Seal of Approval' as an alternative to manufacturer certification. b). Together the full-cutoff mandate, the IDA seal option, and the 3000K cap apply to new and replacement lighting throughout unincorporated Loudoun County; the incorporated towns of Leesburg, Purcellville, Hamilton, Middleburg, Round Hill, Hillsboro, and Lovettsville administer their own lighting rules under separate town codes.
Violations & Fines
Fixtures that are not full cutoff, lack IDA-seal or manufacturer certification, or exceed the 3000K color-temperature cap fail Zoning Administrator review of the required photometric plan and are not approved. Installed noncompliant fixtures are civil violations of the Zoning Ordinance under Section 10.13.E, $200 for the first charge, $500 for each additional charge, each day a separate offense, capped at $5,000 before the County may pursue a criminal misdemeanor under Section 10.13.D.
Frequently Asked Questions
Does Loudoun County follow International Dark-Sky Association standards?
Is there a limit on how bright-white outdoor bulbs can be?
How do I prove a fixture meets the full-cutoff standard?
Sources & Official References
Other rules in Loudoun County
Compare Loudoun County to another location·View the Virginia outdoor lighting overview
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