Williamson County, TN Outdoor Lighting: Light Trespass & Shielding (2026)
Key Facts
- Max illumination at property line
- 0.2 footcandles, all use types
- Direct-shine ban
- No light into adjacent yards/windows
- Wall pack lumen cap
- 1,500 lumens, fully shielded
- Pole-mounted floodlights
- Prohibited outright
- Parking lot uniformity ratio
- 10:1 max-to-min footcandles
- Exempt uses
- Mobile homes, single-family homes, street lights
Summary
Exterior lighting on covered development in unincorporated Williamson County cannot shine directly into a neighbor's yard or windows, and illumination measured at any property line is capped at 0.2 footcandles. Wall packs, floodlights and spotlights all carry their own shielding rules to keep the beam off adjoining land.
(5) Exterior lighting shall not shine directly into the yard or windows of adjacent residential uses. ... a) Wall-mounted lights shall be fully shielded luminaires (such as shoebox or can style fixtures) to prevent the light source from being visible from any adjacent residential property or public street right-of-way. ... b) Such lighting shall be installed in a fixture that is shielded so that no portion of the light bulb extends below the bottom edge or above the top edge of the shield, and the main beam from the light source is not visible from adjacent lands or adjacent rights-of-way. Floodlights or other type of lighting attached to light poles that illuminate the site or building are prohibited.
Full Breakdown
03(B)(5) of the Williamson County Zoning Ordinance bars exterior lighting on covered uses from shining directly into the yard or windows of adjacent residential uses. 2 footcandles across every use classification, agricultural through industrial, regardless of how bright the lighting is inside the site. 03(C)(3) adds fixture-level rules: wall-mounted lights must be fully shielded, shoebox- or can-style luminaires so the light source itself is not visible from any adjacent residential property or public right-of-way, and wall packs are capped at 1,500 lumens and limited to lighting unsafe entrance areas rather than general site illumination.
Floodlights and spotlights under (C)(4) must be aimed and shielded so illumination lands exclusively on the building facade or intended feature, with no part of the bulb extending beyond the shield and the main beam not visible from adjacent land or rights-of-way; lighting attached to light poles that illuminates the site or building is prohibited outright. Parking lots carry a separate uniformity cap under (C)(2) limiting the ratio of maximum to minimum footcandle readings to ten-to-one, so no single fixture can flood light toward a property line. 03(A).
Violations & Fines
Lighting that spills past the 0.2-footcandle property-line cap or shines directly into a neighbor's yard or windows is a zoning violation under Article 22. Section 22.07(A) makes it a misdemeanor punishable by a $10-$50 fine per offense under Tenn. Code Ann. §13-7-111, with each day of continued trespass a separate offense under 22.03(F), and the Codes Compliance Director can pursue civil enforcement or revoke the Zoning Certificate under 22.06 until the fixtures are re-aimed or shielded.
Frequently Asked Questions
How bright can light be at my property line from a neighboring commercial site?
Can a business point a floodlight at my house?
Are wall-mounted lights on a commercial building capped in brightness?
What can I do if a neighboring business's lights shine into my windows?
Sources & Official References
Other rules in Williamson County
Compare Williamson County to another location·View the Tennessee outdoor lighting overview
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