Town of Cohasset, MA Article 15 Accessory Dwelling Unit Special Permit

[Added 3-30-2002 by Art. 18]

§ 300-15.1 Purpose.

A. To provide a useful type of housing to meet the needs of residents.

B. To protect the stability, property values and character of one-family residential neighborhoods and help preserve ownership of one-family dwellings.

C. To facilitate the Town's monitoring of the creation and maintenance of accessory dwelling units.

§ 300-15.2 Special permit conditions.

A. An applicant for an accessory dwelling unit special permit shall be an owner or owners of a detached one-family dwelling (house) with at least a 50% ownership interest and shall have his/her/their primary residence either in the accessory dwelling unit or in the principal dwelling unit within the house.

B. The net floor area of the accessory dwelling unit shall not exceed the lesser of 25% of the net floor area of the house or 900 square feet.

C. The house must have at least 1,200 square feet of net floor area.

D. No accessory dwelling unit special permit granted hereunder shall take effect sooner than 10 years after final certificates of occupancy are issued for the house.

[Amended 4-30-2018 ATM by Art. 19]

E. At least one off-street parking space shall be provided for each bedroom in the accessory dwelling unit in addition to parking required for the house.

F. The exterior appearance of the house shall not be altered by the creation of the accessory dwelling unit except for stairways and exits as required by law, which shall be in the side or rear of the house, and restoration shall be consistent with the original architecture of the house.

G. Outside storage areas shall be screened by fencing or landscaping.

H. Only one house may be present on the lot where the accessory dwelling is to be located.

I. Only one accessory dwelling unit may be created within a house.

J. The lot size must comply with the requirements for a one-family dwelling as set forth under § 300-5.3. This provision shall not apply to lawful, preexisting, nonconforming structures.

K. To qualify for an accessory dwelling unit special permit, for a preexisting, nonconforming structure, per § 300-8.2, the accessory dwelling unit shall be constructed within the living and/or sleeping area of the preexisting structure, shall not be permitted to increase the total square footage of the preexisting structure and shall not alter the footprint of the preexisting structure.

L. Adequate provision shall be made for the disposal of sewage, waste and drainage generated by the occupancy of such accessory dwelling unit and the house and for an adequate water supply to such accessory dwelling unit and the house in accordance with the requirements of the Board of Public Health.

[Amended 5-24-2021 ATM by Art. 28]

M. The accessory dwelling unit and all other modifications to the house shall be designed so that appearance of the house remains that of a one-family dwelling, and the construction and occupancy of the accessory dwelling unit will not be more detrimental to the neighborhood in which the house is located or injurious to persons or property than the existing one-family use.

N. An accessory dwelling unit shall not be occupied as such unless the owner or owners of the house have secured an accessory dwelling unit special permit pursuant to this article. The special permit will be limited to the original applicant(s) and shall terminate upon transfer of ownership of the house.

O. The owner shall notify the Building Inspector, in writing, within six months of the lapse in use of the accessory dwelling unit as such.

[Amended 4-30-2018 ATM by Art. 19]

P. No special permit shall be granted when more than 10% of the single-family dwellings, based on the number of single-family dwellings as per Town of Cohasset Assessor records, have an accessory dwelling unit pursuant to this article.

Q. No more than 10 new accessory dwelling special permits shall be issued by the Zoning Board of Appeals in a single calendar year.

§ 300-15.3 Application procedure.

A. An application for an accessory dwelling unit special permit shall include a site plan and floor plan. When the creation of an accessory dwelling unit involves exterior alteration of the house, per § 300-15.2F, elevation plans shall show the sides of the building affected by the creation of an accessory dwelling unit, before and after the construction of the accessory dwelling unit. These plans shall include, at a minimum, footprint of existing house, location and number of off-street parking spaces, square footage of existing house, square footage of proposed accessory dwelling, and location/means of ingress and egress from the accessory dwelling unit. All plans must be prepared and stamped by a registered professional architect or engineer.

B. An application for an accessory dwelling unit special permit must include a notarized letter stating that the applicant will occupy one of the dwelling units in the house. Every accessory dwelling unit special permit shall include a condition that the applicant will occupy one of the dwelling units in the house.

C. The procedures and requirements stated in this Article 15 for the review and approval or denial of an application for an accessory dwelling unit special permit shall be in addition to the provisions of § 300-12.4 of this Zoning Bylaw, which provisions shall also apply to an application for an accessory dwelling unit special permit.