Wellesley, MA

Wellesley, MA Accessory Dwelling Unit (ADU) Rules

City Acceptance Rating: 6/10

Last updated: 10.29.2024

What You Need To Know

Currently not in compliance with the Massachusetts Affordable Homes Act.

ADU rules in Wellesley are pretty relaxed but still do not conform to the new Affordable Homes Act because of the permits needed and approval from the Planning Department.

Type of ADU Permit Required

ADUs require a building permit from the Inspector of Buildings and an annual certificate from the Planning Department.

ADU Rules

  • ADUs must match the principal dwelling’s style, including siding, roof pitch, trim, windows, and doors.

  • Exterior ADU doors cannot face public streets or private ways unless in pre-existing detached structures.

  • Exterior staircases must be hidden from public view and complement the main dwelling.

  • ADU construction must not exceed the principal dwelling’s height before ADU construction.

  • Detached ADUs are allowed only in the rear or side yard or in pre-existing buildings.

  • ADU size: minimum of 250 sq ft, maximum of 900 sq ft or 50% of the main dwelling’s gross area.

  • ADU must meet all applicable area and yard regulations.

  • Operational Requirements:

    • ADU owners must file a notice with the Registry of Deeds.

    • Owners must reside on the property for at least 184 days per year and cannot lease the owner unit when absent.

    • Minimum lease term for the non-owner-occupied unit is 30 days.

    • No product pickups or deliveries beyond typical residential activities.

    • ADUs cannot be used for a home business.

Resources:

https://wellesleyma.gov/DocumentCenter/View/30044/Section-513-Accessory-Dwelling-Units

Attached ADU, Convert Existing SpaceChris LeeGreater Boston, Massachusetts, Wellesley, Friendliness Score: 6/10