New Bedford, MA Accessory Structures: ADU Rules (2026)

" The Board of Appeals grants the special permit, which under Section 2341 lapses every two years under the general special-permit renewal rules of Section 5300. An applicant must submit a plot plan from a registered land surveyor under Section 2342 showing the existing dwelling, the proposed unit, any septic system, and required parking; a mortgage inspection survey can satisfy this if properly adapted. Section 2343 requires an affidavit certifying that the owner will occupy the primary dwelling for as long as the accessory unit is occupied.

Section 2344 caps the city at one accessory dwelling unit per lot, limits it to 1,000 square feet of floor space, and requires it to be located within the existing residential structure, not a new freestanding building. Section 2345 protects the single-family appearance of the property: construction for the unit cannot increase the structure's gross floor space by more than 15 percent over what existed on December 23, 2003, any new stairways or egress must be enclosed or screened from public view, and the owner must add at least one more parking space finished in materials matching the existing driveway.

On renewal, Section 2346 requires an affidavit that the unit has not been enlarged or altered beyond its original special permit dimensions, and Section 2347 requires a public hearing finding that the unit will not be substantially detrimental to the neighborhood.