The bill amends sections of the General Laws related to zoning ordinances, specifically focusing on the inclusion of provisions for attached single-family dwellings. It introduces new legal language that mandates zoning ordinances to allow the construction of attached single-family units in designated zoning districts. These units are defined as dwellings constructed side by side or horizontally with a party wall and lot line. The bill stipulates that these units must have access to public water and sewer or approved private systems. It allows for specific zoning requirements, such as zero-lot line setbacks along common property lines, and ensures that existing dimensional requirements of the base zoning district apply to the perimeter property lines of the end-units, while prohibiting increased requirements solely for attached single-family structures.

Additionally, the bill specifies that all towns and cities must allow attached single-family units in residential districts that permit the construction of two or more units, with the number of attached single-family units allowed corresponding to the residential density for the property and zoning district. The act is set to take effect on January 1, 2026.