Do I need a permit for a shed in Belmont, Massachusetts?
Yes. Belmont's Zoning By-Law allows tool sheds and similar accessory buildings in residential districts, but caps them at 150 sq ft of floor area and 10 ft in height, and they must sit at least 5 ft from the side and rear lot lines and 5 ft from the house. A shed placed forward of the back wall of your house must meet the full house setbacks.
| Allowed in residential zones | Yes (Y) in Single Residence A-D, General Residence and AH [1] |
| Max size | 150 sq ft floor area (660 sq ft for a garage) [2] |
| Max height | 10 ft (15 ft for a garage) [2] |
| Side and rear setback | 5 ft from side and rear lot lines [3] |
| Distance from house | 5 ft from the principal building [3] |
| Rear yard coverage | Accessory buildings may cover no more than 40% of the rear yard [4] |
| Front/side location | If any part is forward of the house's rear line, the shed must meet dwelling setbacks [5] |
Allowed use
The use table lists "a noncommercial greenhouse; a tool shed used for the storage of tools, yard and household equipment or other similar accessory buildings" as allowed (Y) in the Single Residence, General Residence and AH districts [1].
Size and height
Under Section 4.3.5(b), accessory buildings other than protected ADUs can't exceed 150 sq ft of floor area (660 sq ft for a garage) or a height of 10 ft (15 ft for a garage) [2]. That's smaller than the 200 sq ft state building-permit exemption, so a shed between 150 and 200 sq ft may not need a building permit but would still exceed zoning.
Setbacks and location
Accessory buildings must be at least 5 ft from the side and rear lot lines and 5 ft from the house [3]. All accessory buildings together can cover no more than 40% of the rear yard, measured as the area behind a line extended from the back wall of the house to the side lot lines [4]. If any part of the shed is forward of that rear line, it has to meet the same front, side and rear setbacks as the house; the Zoning Board of Appeals can grant a special permit exemption for corner lots [5]. In practice, put the shed in the back yard.
Lot coverage
Sheds count toward lot coverage, which the by-law defines as the share of the lot covered by buildings or structures, including accessory buildings [6]. Check your district's coverage and open-space limits in Section 4.2 if your lot is already heavily built.
Permits
The Zoning By-Law doesn't set its own shed permit threshold. Under the state building code, a one-story shed of 200 sq ft or less generally doesn't need a building permit, but electrical work does, and zoning rules apply regardless.
See how Belmont compares with 8+ other Massachusetts towns on sheds & accessory buildings →
Next steps
- Keep the shed to 150 sq ft and 10 ft tall or less, behind the rear line of your house.
- Mark the location at least 5 ft from side and rear lot lines and 5 ft from the house; confirm lines with a survey if unsure.
- Ask the Building Division (617-993-2650) whether your shed needs a building permit and whether lot coverage is an issue on your lot.
- If you need a larger shed or a spot forward of the house, ask about zoning relief from the Zoning Board of Appeals.
Common questions
- Do I need a permit for a shed in Belmont, Massachusetts?
- The Zoning By-Law sets no shed permit threshold. Under the state building code, a one-story shed of 200 sq ft or less generally doesn't need a building permit, but electrical work does and zoning rules apply regardless.
- How big can a shed be in Belmont, Massachusetts?
- Accessory buildings like tool sheds are capped at 150 sq ft of floor area and 10 ft in height. That is smaller than the 200 sq ft state exemption, so a shed between 150 and 200 sq ft would still exceed zoning.
- How far from the property line must a shed be in Belmont, Massachusetts?
- At least 5 ft from the side and rear lot lines and 5 ft from the house. A shed forward of the back wall of the house must meet the full house setbacks.
- Is there a limit on how much of my yard sheds can cover in Belmont, Massachusetts?
- Yes. All accessory buildings together can cover no more than 40% of the rear yard.
Massachusetts building code rules for sheds
The Massachusetts State Building Code (780 CMR, 10th edition) sets when a shed needs a building permit. Your town's zoning sets where it can go.
- No building permit needed for a one-story detached accessory structure used as a tool or storage shed, playhouse or similar, if the floor area is 200 sq ft or less (Residential Code R105.2).
- Bigger sheds, or any with more than one story, need a building permit from your local building department.
- Also exempt from a building permit: detached decks of 200 sq ft or less that are no more than 30 inches above grade, and greenhouses covered only in plastic film.
- The exemption covers only the building permit. Electrical, plumbing or gas work in the shed still needs its own permits, and the shed still has to meet local zoning (setbacks, lot coverage, height). Many towns set accessory-structure setbacks even for small sheds.
- Wetlands: putting a shed in a wetland resource area or within 100 feet of a wetland (or 200 feet of a river) may require Conservation Commission approval first, whatever its size.
The 10th edition took effect October 11, 2024 and has been the only code in force since July 1, 2025.
What the bylaw says
- §3.3 Schedule of Use Regulations, Accessory Uses, Zoning By-Law (as amended through March 3, 2025; approved July 2, 2025) - complete town PDF, p. 39
A noncommercial greenhouse; a tool shed used for the storage of tools, yard and household equipment or other similar accessory buildings (see §4.3.5) Y Y Y N N N Y N
- §4.3.5(b)(1) Dimensional Regulations, Zoning By-Law (as amended through March 3, 2025; approved July 2, 2025) - complete town PDF, p. 53
1. Accessory Buildings other than Protected-Use ADUs, as defined in Section 6.14.2, shall not exceed the following: 150 square feet of floor area (660 square feet for a garage) or a height of 10 feet (15 feet for a garage).
- §4.3.5(b)(2) Dimensional Regulations, Zoning By-Law (as amended through March 3, 2025; approved July 2, 2025) - complete town PDF, p. 53
2. Accessory Buildings shall be set back at least five feet from the side line and rear line of the lot and five feet from the principal building to which it is accessory.
- §4.3.5(c)(1) Rear Yard Restrictions, Zoning By-Law (as amended through March 3, 2025; approved July 2, 2025) - complete town PDF, p. 53
1. A building accessory to a dwelling shall cover not more than 40% of the rear yard of the lot.
- §4.3.5(c)(2) Rear Yard Restrictions, Zoning By-Law (as amended through March 3, 2025; approved July 2, 2025) - complete town PDF, p. 53
2. If any part of the accessory building is forward of the rear line of the dwelling, the accessory building shall conform to the front setback, side line and rear line requirements for a dwelling in the district in which the accessory building is located.
- §1.4 Definitions, Lot Coverage, Zoning By-Law (as amended through March 3, 2025; approved July 2, 2025) - complete town PDF, p. 15
Lot Coverage - The percentage of lot area that is covered or occupied by buildings or structures including accessory buildings and accessory buildings and accessory structures.