[Added 3-27-1982 ATM by Art. 37; amended 4-5-1986 ATM by Art. 33; 3-25-2006 ATM by Art. 10; 11-6-2017 STM by Art. 1; 5-15-2021 ATM by Art. 21]
Intent. The intent of this bylaw is to provide the owner of a single-family residence the opportunity to establish an accessory dwelling unit (ADU) in a section of the residence or in an accessory building with no change in the principal use of the premises. The establishment of such ADU will be by special permit issued by the Zoning Board of Appeals, unless otherwise specified below. The outside appearance of the premises shall remain that of a single-family residence. The unit is for the use of a limited number of persons, with no restriction on the relationship of the occupants to the owner. To be considered a separate unit, the ADU must have its own kitchen, sleeping, and interior toilet and bath facilities, as well as a separate entrance. To be considered accessory, the apartment shall be restricted in size relative to the primary residence, and must be clearly accessory and subordinate to the principal use of the premises as a single-family residence. Any such unit shall provide adequate privacy, safety, and convenience for the occupants. Establishment of an ADU shall be as follows:
A. Requirements.
(1) Number and approach: One ADU on a premises can be established, provided the applicant demonstrates adherence with the provisions of this section:
(a) By special permit from the Zoning Board of Appeals; or
(b) By right, provided the unit is designed and constructed according to the age-appropriate design criteria as defined in §
125-57E of the Protective Bylaw.
(2) Dimensional requirements: The unit or units shall meet the following dimensional limitations:
(a) The ADU, whether located in a detached accessory structure or in the primary residence structure, shall occupy a maximum of 1,500 square feet, but in no case shall the total square footage of the ADU exceed 1/2 of the total habitable floor area of the primary residence.
(b) Consistent with minimum square footage (State Sanitary Code, Chapter II, 105 CMR 410.000).
(3) Design: Accessory dwelling units shall be designed and constructed as follows:
(a) The outside appearance of the residence and premises shall remain that of a single-family home.
(b) The ADU shall have its own separate entrance from the outside.
(c) The ADU shall have its own kitchen, sleeping, interior toilet, and bathing facilities.
(d) The rooms in the ADU shall have adequate ventilation and shall have heat that is adequately supplied and controlled.
(e) The ADU shall comply with all health and safety requirements for residences.
(4) Water and wastewater: The creation of any ADU must comply with 310 CMR 15.000: Septic Systems ("Title 5") and its successors and standard Board of Health regulations for any increase in bedrooms being served by the system.
B. Limitations. The special permit and/or building permit shall be issued only if the application contains the following limitations and conditions:
(1) The owner(s) shall continue to reside on the property as their principal residence.
(2) The occupancy of any ADU shall be consistent with the requirements of 105 CMR 410.000.
(3) All turnaround and parking areas shall be provided on the lot. As viewed from the street, turnaround and parking area should be that of a single-family home.
C. Site plan standards. A special permit and/or building permit issued under this section, by itself, does not require separate site plan review under §
125-39. However, if any ADU results in new building area on the lot, an engineered site plan shall be required showing the addition and all relevant zoning dimensions to determine compliance with this section.
D. Review and approval. Accessory dwelling units shall be reviewed based on whether the unit includes age-appropriate design features as follows:
(1) For accessory dwelling units that are not designed according to the age-appropriate design criteria provided in §
125-57E, Age-appropriate design, applicants are required to apply to the Zoning Board of Appeals for a special permit. Applications shall include an application form, filing fee, engineered site plan as applicable, and building plans and elevations showing sufficient detail to determine compliance with this section.
(2) For accessory dwelling units that are designed according to the age-appropriate design criteria provided in §
125-57E, Age-appropriate design, applicants are required to apply to the Building Commissioner for a building permit. Applications shall include an application form, filing fee, engineered site plan as applicable, and building plans and elevations showing sufficient detail to determine compliance with this section.
(3) A copy of the application packet shall be provided to other interested Town boards, officials and departments for advice and recommendations. Board of Health approval shall be required.