BEACON HILL HAS taken repeated swings at getting cities and towns to build more housing over the last five years — sometimes waving carrots and sticks, sometimes making changes to state zoning law to allow more housing by fiat.
But a quirk of state zoning that treats Boston differently is starting to create parallel realities. Just 500 feet apart, across the Neponset River, a single-family homeowner in Milton or Quincy could soon add a second unit or even a third smaller unit without needing special permission from local officials or buy-in from neighbors worried about parking. Or they could be in Boston.
None of the big housing reforms passed recently on Beacon Hill apply to Boston, which is covered by its own state-authorized zoning code, not the code directly changed by legislation, which covers every other municipality in Massachusetts.
Cities and towns from the Cape to the Berkshires now allow small accessory dwelling units to be built in most districts, have a harder time rejecting building variances, and many are covered by higher zoning requirements near transit. And more change is in the works that could boost housing on religiously owned parcels and allow two units to be built on most lots.
These recent moves all work the same way: by amending Chapter 40A of the General Laws, the statute that hands 350 cities and towns their zoning authority. But Boston’s zoning is covered by a separate state statute — the 70-year-old Boston Zoning Enabling Act — and often operates as a world apart from its fellow municipalities.
That is especially significant because Boston is the state’s single major metro area and the driver of the Massachusetts economy, said Luc Schuster, the executive director of Boston Indicators, a research center at the Boston Foundation. Statewide changes can be great, he said, but “there’s a big donut hole in that approach when Boston is exempt.”
Elsewhere, state lawmakers have repeatedly bet that pulling zoning decisions out of local hands will dent a housing shortage of roughly 222,000 units.
The MBTA Communities housing law, passed in 2021, ordered 177 cities and towns served by or near the T to zone at least one multifamily district by right near transit. The state credits it with about 9,000 units sitting in the permitting pipeline so far.
The Affordable Homes Act, signed in 2024, legalized small accessory dwelling units like in-law apartments and backyard cottages in single-family districts statewide. Cities and towns issued just over 1,200 ADU permits in the law’s first year, short of the administration’s own target of 1,600 to 2,000 annually, because of macroeconomic costs and a tangle of local wetlands, septic, and building-code rules. During the first half of 2026, the Healey administration says 854 new ADUs were approved.
This summer brought a subtler change, as the fiscal 2027 budget scrapped the decades-old “substantial hardship” test that zoning boards statewide used to decide if someone had to follow zoning rules exactly. In its place is “practical difficulty.”
“That looks like a small word swap. It is not,” wrote real estate analyst Steve Novak. “It moves Massachusetts from one of the hardest variance standards in the nation to one that looks like the standards most other states already use for this kind of dimensional relief.”
Two major zoning reforms are still being negotiated. The Senate’s version of a sweeping economic development bill would legalize duplexes by right on any residential lot. Stacked on top of the ADU law, on paper, most residential lots in the state could become three-unit parcels. The chamber’s summary doesn’t offer an estimate of how many new housing units it could generate, just that it would “vastly expand” the state’s housing potential.
The House’s version of the economic development bill would make it easier for religious institutions to build apartments on land they own. Backers of the so-called Yes in God’s Backyard, or YIGBY, reforms point to an analysis of religiously owned land in the state that found faith-based organizations control about 4,800 developable parcels totaling more than 20,000 acres across the Commonwealth, including in Boston.
“Number one, we have a massive housing shortage and I’m a huge proponent of swinging big for statewide zoning reform,” Schuster said. While many municipalities go further than state standards, “housing markets function regionally and people live regionally, so it’s a policy domain that we just need to tackle at a much higher level of government,” he said.
None of these recent measures, as written, would change a single line in Boston’s famously tangled zoning code. City officials insist that, with its own separate zoning code and community comment process, Boston is already doing more than other communities to promote housing growth.
“In many respects, these changes mirror locally tailored zoning reforms that the city has adopted to make it easier to build the homes our residents need,” a city spokesperson said in a statement. “In Boston, existing zoning already allows for greater density than this state provision enables,” referring to the duplex proposal.
Though the city is engaged in targeted neighborhood rezoning efforts, narrowly out-builds its neighbors, and boasts higher rates of subsidized affordable housing than San Francisco or New York, its tight housing pipeline is keeping rents persistently high.
“Boston can say they know what to do, but they have not done it,” said Jesse Kanson-Benanav, executive director of pro-housing group Abundant Housing Massachusetts. He noted that Mayor Michelle Wu announced in her 2024 State of the City speech that they would legalize ADUs by-right all across the city that year.
Two years later, detached ADUs are still limited to owner-occupied properties in Mattapan and East Boston. Just over 50 have been permitted. The state law allows attached or detached ADUs and forbids municipalities from requiring owner occupancy or a family relationship for the ADU or the main building.
About 33 percent of Boston’s residential land is zoned as single-family. The duplex provision being considered by the Legislature would override all single-family zoning with two-family zoning for every community except Boston.
“We like to think Boston is especially unique, but we are a city in a state, just like every other city in a state in the country,” Kanson-Benanav said. “We just have this unique element in relation to the state zoning code.”
As the Democratic primaries loom nearer, Beacon Hill is touting the policies that it does have in hand, not eagerly barreling toward legislation targeting Boston’s unique status.
State Sen. Julian Cyr, the chamber’s housing chair who represents the Cape and Islands, highlighted the array of policy changes packed into bigger bills this session. Zoning changes and permitting reforms should ease the way for new housing in most of the state, lawmakers say. Boston isn’t off the table, but it wasn’t on the menu this session.
“Despite this encouraging process, we have a lot more to do on housing and I fully expect us to come back next session and do more here,” Cyr said. “We have to have a conversation about how we build housing in each and every community, including Boston, and it’s one I am eager to have.”
