Key Requirements
Permit Type
Site Plan Review
Permit Authority
Board of Appeals
Local Terminology
PADU
Max Size (sq ft)
900
Max Size (% of principal)
50%
Size Rule
Whichever is smaller
Attached Allowed
Yes
Detached Allowed
Yes
Internal Allowed
Yes
Parking Spaces Required
1
Transit Exemption
No
Short-Term Rental
Prohibited
Owner Occupancy Required
No
Design Review Required
Yes
Historic District Review
Yes
Energy Code
Stretch Code
HERS Rating Required
Yes
Max HERS Index (ADU)
52
Quick Summary
- Boxford adopted its Protected Use ADU bylaw (Article 22, Appendix D, Section G) at Town Meeting on May 13, 2025, to comply with the Affordable Homes Act.
- ADUs are permitted by right in the R-A Zoning District only (Boxford is primarily R-A Residence-Agricultural), with Site Plan Approval from the Board of Appeals required.
- Fire Department review, approval, and sign-off is required before the Site Plan can be submitted.
- Short-term rentals are prohibited -- ADUs may not be rented for less than 31 consecutive days.
- The ADU cannot be legally separated or conveyed apart from the principal dwelling (no condo-ization).
Requirements at a Glance
| Requirement | Rule |
|---|---|
| Permit type | By right with Site Plan Approval from Board of Appeals |
| Max size | 900 sq ft or 50% of principal dwelling GFA, whichever is smaller |
| Max stories | 2 |
| Types allowed | Attached, detached, internal, conversion of existing non-residential accessory structure |
| Owner occupancy | Not required (preempted by state law) |
| Separate ownership | Not allowed; ADU cannot be conveyed apart from principal dwelling |
| Parking | 1 space required; tandem parking prohibited |
| Short-term rental | Prohibited (minimum 31 consecutive days) |
| Districts | R-A only (prohibited in all other districts) |
| Fire Dept review | Required before Site Plan submission |
| Historic district | Historic District Commission approval required |
| Design review | Architectural compatibility with principal dwelling required |
| Front setback | ADU cannot be closer to front lot line than primary dwelling |
| New garage | Requires Special Permit; max one attached garage |
| Trailers | Not allowed as ADUs |
ADU Questions in Boxford
Can I build an ADU in Boxford, MA?
Yes, but Boxford requires site plan review before a permit is issued. That is an administrative review of layout, access, and drainage — a lower bar than a special permit, though it does add time to the schedule. Review is handled by the Board of Appeals. Boxford calls these "PADU."
How big can an ADU be in Boxford, MA?
Boxford limits an accessory dwelling unit to 900 square feet or 50% of the principal dwelling, whichever is smaller. State law protects ADUs up to 900 square feet on single-family lots, so a town cannot enforce a smaller cap on a protected-use ADU.
What types of ADU are allowed in Boxford, MA?
Boxford permits 3 forms of accessory dwelling unit: detached (a separate structure in the yard); attached (an addition to the house); internal (a conversion of existing space). Which one makes sense usually comes down to your lot, your septic or sewer situation, and whether you want the unit connected to the main house.
Does Boxford, MA require extra parking for an ADU?
Boxford's bylaw calls for 1 additional off-street parking space(s) for an ADU. Under state law, towns cannot require more than one space for a protected-use ADU, and no parking at all can be required within a half mile of transit.
Do I have to live on the property to rent out an ADU in Boxford, MA?
No. Boxford does not impose an owner-occupancy requirement, and state law bars towns from requiring it for protected-use ADUs. You can rent the unit without living on site.
What energy code applies to an ADU in Boxford, MA?
Boxford has adopted the Stretch Energy Code. That means a new ADU must hit a HERS rating of 52 or lower, which drives real decisions about insulation, air sealing, windows, and heating — typically an all-electric heat pump system. Budget for a HERS rater on the project from day one.
Can I use an ADU in Boxford, MA as a short-term rental?
No. Boxford prohibits using an accessory dwelling unit as a short-term rental; the minimum lease term is 31 days. The unit is intended for long-term housing. State law expressly allows towns to restrict short-term rental of ADUs, so this restriction does hold up.
Based on Boxford’s bylaw as last verified 2026-02-25. Bylaws change at annual town meetings — confirm with the local building department before you build.