Accessory dwelling units are now permitted by right in single-family zoning districts across Massachusetts. In the Berkshires, municipalities are still working to bring local bylaws into compliance with the state law.
For years, Massachusetts has left it to individual towns and cities to define what is an accessory dwelling unit, or ADU, to set restrictions and to decide whether to allow them at all. But as the housing crisis has deepened, officials looked to streamline regulations and cut away some of the red-tape that has prevented the construction of ADUs, which some would know as in-law apartments.