If you build additions, garages or small homes, the backyard cottage business in Massachusetts keeps getting bigger. On Oct. 15, Gov. Maura Healey stood in Lexington and announced another $5 million to make accessory dwelling units, or ADUs, easier and cheaper to build.
According to the governor's announcement, the new money brings the state's total commitment to ADUs to $15 million. More than 2,000 ADUs have already been approved since the Affordable Homes Act made them easier to build statewide.
"We made it easier to build ADUs across Massachusetts, and more than 2,000 have already been approved," Healey said. "Now we're investing another $5 million to build even more homes and help homeowners get their projects off the ground."
A new pilot for developers
The new $5 million Community ADU Pilot Program will give financial help to qualified affordable housing developers to build income-restricted ADUs on properties they already control. The program is run by the Massachusetts Housing Partnership (MHP) and funded by the Executive Office of Housing and Livable Communities. The state expects it to support 20 to 30 affordable ADUs.
Lexington offered an example. The nonprofit Lexington Housing Assistance Board, or LexHAB, which has worked for more than four decades to create and preserve affordable housing, is moving forward with four income-restricted ADUs.
"What I've seen from the Governor, the Lieutenant Governor and the Secretary is a real willingness to think outside the box," said Tara Mizrahi, a LexHAB board member and president of Affirmative Investments.
More help for homeowners
The state also announced the coming second phase of MHP's $10 million ADU Incentive Program.
The first phase launched in July and offers low-cost feasibility studies to help homeowners figure out whether an ADU will work on their property. In the first eight weeks, more than 350 studies were underway or completed, according to the state.
The second phase will use what those studies turned up to identify the common costs that keep homeowners from moving from planning to construction. MHP will then provide financial help with eligible expenses to get those projects moving.
"Making ADUs possible statewide was a critical milestone. Now we need to help homeowners and affordable housing developers turn that opportunity into homes," said MHP Executive Director Rachel Heller.
The state has also partnered with MassHousing to offer low-interest loans to homeowners who want to build an ADU, and its ADU Design Challenge provides publicly available designs to help cut planning costs.
The Executive Office of Housing and Livable Communities recently finished a public comment period on proposed changes to the state's ADU regulations. The changes are meant to clarify local permitting requirements, reduce barriers to construction and streamline the process. Comments from residents, towns, housing providers and others will shape the final version.
Before the Affordable Homes Act was signed in 2024, Massachusetts had no consistent statewide standard for ADUs. The state says a patchwork of owner-occupancy rules, size limits, design reviews and discretionary approvals often made ADUs hard or impossible to build.
The law changed that. It allows one ADU of up to 900 square feet, or no more than half the gross floor area of the main house, to be built by right on lots where single-family homes are allowed, subject to reasonable local requirements. Boston has its own zoning authority and its own ADU rules.
"ADUs are a great way to create more housing in our existing neighborhoods and give residents more options for where and how they live," said Lt. Gov. Kim Driscoll.
Why it matters for Contractors
ADUs are right in the wheelhouse of small builders, remodelers and modular companies, and the numbers keep climbing: more than 2,000 approved, 350-plus feasibility studies in the pipeline and now money aimed at the costs that stall projects. Every homeowner who finishes a feasibility study is a potential customer looking for someone to price and build the job. The new developer pilot adds another kind of client, nonprofits like LexHAB building small, income-restricted units on land they already own. And if the regulation changes do clarify local permitting, contractors should have fewer surprises at the building department. It's worth getting to know MHP's programs so you can walk customers through the help available.