ADUs Turn One
Regulatory Barriers to Production in Massachusetts and Ideas for Further Reform
May 20, 2026
In 2024, the passage of the Affordable Homes Act cleared the way for statewide permitting by right for accessory dwelling units in Massachusetts. One year after the new law was enacted, has the change made a difference?
A new report from Boston Indicators, the research center at the Boston Foundation, and Abundant Housing Massachusetts finds that the new statewide permitting pathway for ADUs has sparked notable growth in the number of ADU permit applications and built units. But the report also notes that ADU production still lags the pace needed to reduce the state’s housing shortfall, with construction costs compounded by local regulations that delay or derail homeowners’ plans.
In the report, lead author Amy Dain, Senior Fellow at Boston Indicators, looks both at the growth of ADU construction in 2025, and at the challenges facing local property owners who benefitted from state-level legalization but now face a range of local building, fire, energy, septic system, wetlands, and stormwater rules.
