Do I need a permit for a shed in Lexington, Massachusetts?
Yes. In Lexington you can place one small shed (under 150 sq ft, no more than 12 feet tall or long) in a side or rear yard as close as 5 feet to the lot line. Larger sheds must meet the normal building setbacks, which in the RO and RS districts are 30 feet from the front and 15 feet from side and rear lot lines.
| Small shed in side/rear yard | One allowed, at least 5 ft from lot line [1] |
| Small shed size limit | Under 150 sq ft; height and length 12 ft or less [1] |
| Front setback (RO, RS) | 30 feet [3] |
| Side setback (RO, RS) | 15 feet [4] |
| Rear setback (RO, RS) | 15 feet [5] |
| Accessory use size cap | 25% of lot area or 25% of gross floor area [6] |
The small-shed exception
These rules come from the Zoning Bylaw PDF incorporating amendments through Annual Town Meeting 2025; the only later zoning change we know of (2026) was described as technical corrections.
Lexington's Zoning Bylaw §4.2.6 lets you put one accessory building, such as a tool or storage shed, in a side or rear yard no closer than 5 feet to a lot line, as long as it covers less than 150 square feet and neither its height nor its length is more than 12 feet [1]. Garages and chicken coops don't qualify for this exception.
Larger sheds and other accessory buildings
Any building or structure that doesn't fit the exception has to comply with the Table 2 dimensional controls [2]. In the RO and RS one-family districts that means:
Table 2 gives RS and RT a single shared column, so the two-family RT district has the same 30/15/15 yards as RS. Table 2's height limit for buildings in RO, RS and RT is 2.5 stories and 40 feet. The bylaw doesn't set a separate height limit for accessory buildings outside the small-shed exception.
Size limits
An accessory use can't take up more than 25% of the lot area or 25% of the gross floor area on the lot [6]. Accessory buildings also count toward the town's residential gross floor area limits (§4.4) if they have floor area.
Nonconforming lots
On a lot with a nonconforming one- or two-family house, the Building Commissioner can approve a new accessory structure by right if it doesn't increase the nonconforming nature of the property (§8.4.1).
Building permit
The local sources don't set a shed permit threshold. Under the state building code, a one-story detached storage shed of 200 sq ft or less doesn't need a building permit, but it still has to meet the zoning setbacks above. Sheds in the floodplain overlay or near wetlands may need extra review.
See how Lexington compares with 8+ other Massachusetts towns on sheds & accessory buildings →
Next steps
- Measure your shed: under 150 sq ft and no more than 12 feet tall or long qualifies for the 5-foot side/rear setback.
- For anything larger, site it at least 15 feet from side and rear lot lines and 30 feet from the front (RO/RS).
- If the shed is over 200 sq ft or more than one story, apply for a building permit at the Building Office (781-698-4530) with a plot plan showing distances to lot lines.
- If the site is within 100 feet of a wetland or in a flood zone, check with the Conservation Commission first.
Common questions
- Can I build a shed in Lexington, Massachusetts?
- Yes. You can place one small shed (under 150 sq ft, no more than 12 feet tall or long) in a side or rear yard as close as 5 feet to the lot line.
- How close to the property line can a larger shed be in Lexington, Massachusetts?
- Larger sheds must meet the normal building setbacks, which in the RO and RS districts are 30 feet from the front and 15 feet from side and rear lot lines.
- Do I need a building permit for a shed in Lexington, Massachusetts?
- If the shed is over 200 sq ft or more than one story, apply for a building permit at the Building Office with a plot plan.
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
- §4.2.6 Accessory Buildings in Setbacks, Zoning Bylaw, Chapter 135 (incorporating amendments through Annual Town Meeting 2025), p. 12
4.2.6 Accessory Buildings in Setbacks. One accessory building, including tool or storage sheds for household equipment or other similar accessory use, but, for the purposes of this section, not including garages or chicken coops, may be located in a side or rear yard, but no closer than five feet to a lot line, provided that the accessory building covers less than 150 square feet and that neither the height nor the length of such accessory building is greater than 12 feet.
- §4.1.1 Applicability, Zoning Bylaw, Chapter 135 (incorporating amendments through Annual Town Meeting 2025), p. 10
4.1.1 Applicability. Each use, building, or structure must comply with the standards described in Table 2, Schedule of Dimensional Controls, except where provided otherwise by this bylaw.
- Table 2, Schedule of Dimensional Controls (columns GC, RO, RS & RT, CN, CRS), Zoning Bylaw, Chapter 135 (incorporating amendments through Annual Town Meeting 2025), p. 142
Minimum front yard in NR 30 30 30 30
- Table 2, Schedule of Dimensional Controls (columns GC, RO, RS & RT, CN, CRS), Zoning Bylaw, Chapter 135 (incorporating amendments through Annual Town Meeting 2025), p. 142
Minimum side yard in NR 15(d)(i) 15(d)(i) 20 20
- Table 2, Schedule of Dimensional Controls (columns GC, RO, RS & RT, CN, CRS), Zoning Bylaw, Chapter 135 (incorporating amendments through Annual Town Meeting 2025), p. 142
Minimum rear yard in NR 15(d) 15(d) 20 20
- §3.2.2 Limit on Size of Accessory Uses, Zoning Bylaw, Chapter 135 (incorporating amendments through Annual Town Meeting 2025), p. 9
3.2.2 Limit on Size of Accessory Uses. An accessory use may not occupy more than 25% of the area of a lot or more than 25% of the gross floor area on a lot.