Nashua, NH Outdoor Lighting: Dark Sky Rules (2026)
Key Facts
- Property-line limit
- 0.2 footcandles maximum
- Shielding trigger
- over 1,800 lumens (900 flood/spot)
- Shielding standard
- ≤3% light above horizontal
- Max mounting height
- 25 feet, formula-capped
- Exempt zones
- D-1 and D-3 Downtown Districts
Summary
Nashua's Zoning Ordinance caps outdoor light spillover at 0.2 footcandles at any property line and requires most fixtures over 1,800 lumens to be shielded so no more than 3% of their output escapes above horizontal.
Light levels shall not exceed 0.2 footcandles at any property line. This subsection does not apply if any property line that separates two or more lots or parcels under common ownership or similar adjacent uses, including:
(1) Multiple and single lots held in common ownership and separate ownership that are subject to a common site plan approval; and
(2) Contiguous parcels, with or without an approved site plan (common to both or separate), that share common access or parking.
B. Any luminaire with a lamp or lamps rated at a total of more than 1800 lumens, and all flood or spot luminaires with a lamp or lamps rated at a total of more than 900 lumens, shall not emit more than 3% direct light above a horizontal plane through the lowest direct-light-emitting part of the luminaire.
C. Any luminaire with a lamp or lamps rated at a total of more than 1800 lumens, and all flood or spot luminaires with a lamp or lamps rated at a total of more than 900 lumens, shall be mounted at a height equal to or less than the value 3 + (D/3), where D is the distance in feet to the nearest property boundary. The maximum height of the luminaire shall not exceed 25 feet.
D. Any temporary outdoor lighting that conforms to the requirements of this section of this section is permitted.
E. The applicant shall submit a lighting plan as required by § 190-275.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: rev 4805762; v29 updated 2026-02-10; through 02-10-2026).
Full Breakdown
Chapter 190, Article IX (Lighting) of Nashua's Land Use ordinance applies to all public and private outdoor lighting citywide except the D-1 and D-3 Downtown Districts. Light levels can't exceed 0.2 footcandles at any property line. Any luminaire rated above 1,800 total lumens, or any flood/spot luminaire above 900 lumens, must be shielded so no more than 3% of its direct light escapes above a horizontal plane through the lowest light-emitting point, and its mounting height is capped at 3 + (distance to the property line ÷ 3) feet, up to a 25-foot maximum. Small fixtures, street lights, sign lighting, temporary construction lighting and emergency lighting are exempt. The Planning Board can grant waivers under § 190-148.
Violations & Fines
Enforced by Nashua's Code Enforcement Department and Zoning Administrator as a Land Use Ordinance violation; nonconforming fixtures that are replaced or relocated must be brought into compliance with current shielding and height limits.
Frequently Asked Questions
Does Nashua require shielded, dark-sky-friendly outdoor lighting?
Is there a limit on light spilling onto neighboring property?
Are small residential lights exempt from Nashua's lighting rules?
Sources & Official References
Other rules in Nashua
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