Harrisburg, PA Outdoor Lighting: Light Trespass & Shielding (2026)

Harrisburg writes its light trespass rule as a measurable number, not a general nuisance standard. Section 7-331.9(C) of the zoning code says any exterior light source shall not cause light spillover onto residential properties in excess of 0.5 horizontal footcandle when measured by a hand-held NIST-certified light meter at the property line on the ground surface. The reading is taken at the property line, on the ground, with a horizontal meter orientation, so the test point is the boundary of the neighbor's lot and not a window or a wall.

The number protects residential properties. The sentence is written for spillover onto residential properties, and it covers any exterior light source in any zoning district, because § 7-331.2(A) requires all uses and activities in all zoning districts to comply with the chapter. Section 7-331.9(A) removes one category: the section does not apply to streetlighting that is owned, financed, or maintained by the City or the state.

Verification is built into subsection (G). The Zoning Officer can require a lighting study to be performed by a qualified professional, which is the route to documenting readings and fixture layouts before or after a complaint. For parking lots, § 7-327.12 requires the applicant to certify that proposed lighting meets published illumination standards established by the Illuminating Engineering Society (IES) or another generally acceptable professional organization, and cross-references Chapter 7-331. Sign lighting is tied in as well: § 7-325.11(A) says to see Chapter 7-331 regarding light and glare control.

The spillover cap sits next to related controls in the same section. Light sources must be shielded and directed to prevent a nuisance to residents in adjacent dwellings or undeveloped residentially zoned areas, and a luminaire within 200 feet of a dwelling or residential district cannot be placed higher than 25 feet above the average surrounding ground level, with exceptions for air safety lights, lights solely illuminating an architectural feature, and lights for publicly owned recreation facilities. The purpose clause in § 7-331.1 ties all of this to reducing the impact of lighting on adjacent properties and public health and safety.