Flagstaff, AZ Outdoor Lighting: Light Trespass & Shielding (2026)

Flagstaff's light trespass rule sits in the outdoor lighting division's general requirements, Section 10-50.70.050.E, and applies to every Outdoor Light Fixture in the City, including motion sensing lighting. The baseline rule is simple: fixtures must be located, aimed, and shielded so the direct illumination they produce is confined to the property boundaries of the source, meaning a neighbor's yard or the street should not receive direct light from someone else's fixture. The code adds a specific, numeric trigger for the brightest fixtures: any privately or publicly owned Outdoor Light Fixture that puts out more than 10,000 lumens and sits within 50 feet of a residential lot, including multifamily development, or of a public right-of-way, must be fitted with an internal or external shield.

That shield, together with the fixture itself, has to be oriented to prevent direct illumination from crossing the adjacent property or right-of-way line, and if the property owner uses an external shield rather than a fixture with internal shielding, the shield's surface must be painted black to cut down on reflected glare, per the configurations illustrated in Figure 10-50.70.050.E. This light trespass standard layers on top of the general shielding and total-lumen-output limits in the rest of Section 10-50.70.050, so a fixture can meet the zone's overall lumen cap and still be out of compliance if its beam crosses a residential property line.