The proposed bill introduces the "Multifamily Housing Act" as a new chapter in Title 45 of the General Laws, aimed at encouraging the development of higher-density, mixed-use, and walkable urban communities. It establishes a base density requirement of at least two units per parcel for new construction in urban areas, specifically in municipalities with populations of 40,000 or more. The bill defines various types of middle housing, including duplexes, triplexes, quadplexes, cottage clusters, and townhouses, and permits their development in areas zoned for residential use that currently allow single-family dwellings.

Local governing bodies are granted the authority to regulate the site and design of middle housing, provided that such regulations do not, individually or cumulatively, discourage the development of all permitted middle housing types through unreasonable costs or delays. The bill specifies that it does not apply to municipalities with populations under 40,000, lands not within an urban growth boundary, or lands not zoned for residential use, including those primarily zoned for commercial, industrial, or agricultural purposes, as well as public uses or lands under interim zoning designations.

Additionally, the bill allows local governing bodies to permit single-family dwellings in areas zoned for single-family use and middle housing in areas not required under this section. The state building code standards committee is tasked with developing a model middle housing ordinance by December 31, 2026. Municipalities may designate zones that exempt properties within those zones from compliance with this section, with a one percent exclusionary zoning transactional fee applied to properties within those zones, which will be remitted to Rhode Island housing to support affordable housing grant programs. The act is set to take effect upon passage.