Leominster's Accessory Structures: The Rules That Matter
Every city handles accessory structures a little differently. In Leominster, Massachusetts, there are 2 distinct rules that residents and property owners should be aware of. Some are stricter than what neighboring cities enforce, and others are more relaxed. Here is what you need to know.
ADU Rules
Leominster allows one accessory dwelling unit by right in any Residential district under Article XV of the zoning ordinance, adopted February 25, 2026. An ADU is capped at 900 square feet or half the principal home's floor area, whichever is smaller, and generally needs one added off-street parking space.
Key details: Right to build: One ADU by right in Residential districts. Size cap: 900 sq ft or half main home's area. Parking: 1 added space unless near transit. Driveway: No new driveway/curb cut allowed. Grandfathering: Pre-9/12/2005 ADUs if permitted.
Building an ADU without a permit, exceeding the 900-square-foot/half-floor-area cap, adding a second ADU on the same lot, or cutting a new driveway where none is allowed under Sec. 22-90.1.4 violates Article XV and the zoning ordinance's general penalty in Sec. 22-15: up to $300 per violation, with each day counted separately, enforced by the director of inspections, who may also withhold occupancy or building permits under Sec. 22-7 and Sec. 22-8.
Shed & Carport Rules
In Leominster, Massachusetts, a detached shed or garage that is not used for human occupancy and is no more than one story tall must sit at least five feet off any side or rear lot line under City Code § 22-37. The same section caps how much of a required side or rear yard any accessory structure, or combination of them, may cover.
Key details: Setback (non-occupied shed): 5 feet from side or rear lot line. Distance from principal building: 10 ft (1-story), 15 ft (taller). Max yard coverage: 25% of required side/rear yard. Front-yard sheds: Barred unless pre-existing before May 1, 2025. Fine: Up to $300 per day of violation.
The director of inspections enforces Leominster's zoning ordinance and will withhold or revoke a building permit for a shed or accessory structure that does not meet these setbacks. Under Section 22-15, a zoning violation carries a fine of up to three hundred dollars per violation, with each day the violation continues counted as a separate offense; the city may instead pursue noncriminal disposition tickets of one hundred, two hundred, then three hundred dollars for repeat offenses.
The Bottom Line
Leominster's accessory structures rules are a mixed bag. Some areas are strict, others are relaxed, and the details matter. The best approach is to check the specific rule that applies to your situation rather than assuming Leominster is broadly strict or permissive.
Keep in mind that Leominster can amend these rules at any council meeting. For the most current version of any rule mentioned here, check the specific ordinance page, where we track updates as they happen.