Judi Barrett
Massachusetts is once again confronting its housing crisis, this time by looking in its own backyards. A new law, in effect since February, allows accessory dwelling units, or ADUs, “by right” across the commonwealth.
These units can be up to 900 square feet or half the size of the main house, whichever is smaller. Cities and towns may impose only “reasonable” restrictions, such as requiring minimum setbacks or prohibiting short-term rentals. Homeowner occupancy cannot be required, and local boards can issue only limited discretionary permits – properties needing special approval on a case-by-case basis.
ADUs do hold promise. They can help older homeowners age in place, provide space for adult children or caregivers and expand rental options without changing a neighborhood’s character. Many homeowners will welcome the chance to supplement their income or make better use of their property.
But as someone who’s spent decades working with communities on affordable housing and fair housing policy, I have to offer a word of caution: ADUs are not a panacea for Massachusetts’ housing crisis.
They Aren’t Affordable Housing
Most homeowners who build ADUs aren’t doing it to solve a housing crisis; they’re doing it to meet a family necessity or to achieve personal financial benefit. That’s entirely reasonable, but it also means these new units will reflect the property owner’s interests and the realities of the private market when they’re offered to the public for rent.
Without public subsidies or regulations, ADU rentals are unlikely to be affordable to people most in need. Even if every eligible homeowner built an ADU, the total number of units would still fall far short of what’s needed – both in scale and in affordability – to meet the commonwealth’s housing deficit. The state may gain thousands of new units, but very few will reach the people for whom the housing market is already out of reach.
Another caution is that, if municipalities can point to a handful of new backyard apartments as evidence of “housing progress,” they may feel less pressure to do the harder work of removing zoning barriers to missing-middle housing, investing in affordable developments, and adopting inclusionary housing policies that create equitable access and lasting affordability. Pointing to ADUs as proof of progress lets municipalities avoid the harder, long-term work of planning for real affordability.
We also must ask, who gets access to these new homes? Because ADUs depend entirely on private homeowner control, decisions about occupancy rest with individuals – not housing authorities, nonprofits or programs with fair housing requirements. That means eligibility does not consider housing needs or equity, but only personal choices made by property owners.
When homeowners alone decide who can rent an ADU, it is far more challenging to enforce basic social fairness in access to housing.
Most Will Be in Wealthy Areas
Even with the new law in place, significant barriers remain. Construction costs are high (due in part to tariffs on already expensive lumber), financing is difficult and many properties face physical or septic system constraints. Building an ADU may simply be out of reach for low and even moderate-income homeowners. As a result, most new ADUs will likely appear in wealthier communities, where land, credit and cash make them feasible.
If we truly want a Massachusetts where everyone can afford to live, work and remain part of their communities, ADUs have a place, but only as a part of a broader housing strategy.
We need inclusionary zoning that ensures new multifamily and missing-middle housing developments – projects that can deliver housing at scale – contribute to long-term affordability and offer a far greater promise of fair housing rights.
We need targeted public investment in affordable and mixed-income housing.
We also need a framework to track whether ADUs are actually reaching the households they were meant to help. Without that oversight, even thousands of new ADUs may do little to address the persistent inequities in our housing market.
The state’s new ADU law is a step toward a hoped-for solution, and it deserves credit. It empowers homeowners, and signals that Massachusetts is ready to modernize its approach to housing. But flexibility alone falls short of fairness; the problem is expecting private solutions to achieve public goals in a market that rewards high rents.
Massachusetts deserves a housing strategy grounded in equity, not quick fixes – one that makes room for everyone, not just those who can afford to build a second unit in the backyard.
Judi Barrett is the owner and managing director of Hingham-based Barrett Planning Group.
