General requirements

A. An accessory dwelling unit ("ADU") that meets the requirements set forth herein shall be a permitted use in all residential zoning districts. An ADU that meets these requirements shall be permitted through an administrative building permit process only.
B. One ADU per lot shall be allowed by right under the following circumstances:
- (1) On an owner-occupied property as a reasonable accommodation for family members with disabilities; or
- (2) On a lot with a total lot area of 20,000 sq. ft. or more for which the primary use is residential; or
- (3) Where the proposed ADU is located within the existing footprint of the primary structure or existing accessory attached or detached structure and does not expand the footprint of the structure.
C. The maximum unit size for an ADU shall be as follows:
- (1) For a studio or one-bedroom ADU, 900 sq. ft. or 60% of the floor area of the principal dwelling, whichever is less; and
- (2) For a two-bedroom ADU, 1,200 sq. ft., or 60% of the floor area of the principal dwelling, whichever is less.
D. Occupants of the ADU shall not be restricted based on familial relationships or age unless such restriction is necessary to comply with the terms of the federal subsidy related to affordability.
E. Application or permitting fees for the creation of an ADU shall not exceed those that would be charged for a new single-family dwelling.
F. Infrastructure improvements in connection with the ADU, including, but not limited to, separate water or sewer service lines or expanded septic system capacity, shall not be required unless such improvements and/or modifications are required by an applicable state agency for compliance under state law or regulation, or to comply with building code requirements, or to address capacity or upgrades necessary to accommodate the ADU.
G. Dimensional requirements and other development standards for an ADU shall not exceed the requirements for an accessory structure in the same zoning district.
H. For conforming lots or legal nonconforming lots of record, neither additional lot area, lot frontage, nor lot width shall be required solely to accommodate an ADU.
I. For ADU applications proposed within an existing footprint of a primary or accessory structure that is legally nonconforming by dimension, zoning relief to address the existing dimensional nonconformity shall not be required.
J. One off-street parking space per bedroom of the ADU shall be required.
K. An ADU shall have no more than two bedrooms.
L. An ADU need not be deed-restricted as affordable housing unless the ADU is part of a comprehensive permit application or is proposed to fulfill the requirements of inclusionary zoning.
M. An ADU may be maintained upon transfer of title or occupancy, and the permitted status of the ADU shall not be revoked based on transfer of title or occupancy alone.
N. The procedure for review of a proposed ADU shall be as follows:
- (1) An application for an ADU that is not allowed by right under this section shall not, by itself, be reviewed as a land development project.
- (2) ADUs may be proposed as part of applications for new primary dwelling units or subdivisions. For proposed ADUs that are part of a larger development proposal, a municipality shall not count such ADUs toward density of the proposal for purposes of limiting the number of dwelling units allowed in such development proposal.
O. ADUs shall not be offered or rented for tourist or transient use or through a hosting platform, as such terms are defined by R.I.G.L. § 42-63.1-2.