Two triple-deckers on Washington Street in Roslindale are seen in 2023. Photo by James Sanna | Banker & Tradesman Staff / File
It’s been the darling of local architects and zoning wonks, but triple-deckers keep running into a major obstacle: They’re illegal to build in nearly two-thirds of Boston.
But the excitement evident among Boston City Council meeting Wednesday showed the door might be cracking open to re-legalizing three- and four-family buildings in many parts of the city.
Every one of the council’s 12 members, minus South Boston and Chinatown’s Ed Flynn, signed on to co-sponsor an order from at-large Councilor Henry Santana, Beacon Hill Councilor Sharon Durkan and Hyde Park-Roxbury Councilor Enrique Pepén to hold a hearing that would investigate how to legalize “construction of triple-deckers and other 2-4 unit housing.”
The measure passed unanimously Wednesday, and sets up hearing at the Committee on Planning, Development & Transportation at a later date, with representatives from the Boston Planning Department invited to present.
That hearing could lead to the drafting of new zoning.
Triple-Deckers Illegal in Many Areas
While a popular housing type in New England’s working-class and middle-class residential neighborhoods in the 1800s, by the 1930s they were banned in many cities, including Boston, amid an anti-immigrant and racist backlash against multifamily housing.
Three-family homes currently are allowed in some zoning subdistricts in Allston, Brighton, Jamaica Plain, Roslindale, Roxbury and West Roxbury. Three-family zoning as-of-right was added in portions of East Boston and Mattapan in 2024 as part of neighborhood-wide upzonings. But many residential zoning districts in Boston limit new homes to 2.5 stories.
Somerville recently re-legalized triple-deckers citywide to address its obligations under the MBTA Communities Act, which doesn’t apply to Boston. And early this year Cambridge officials legalized 4-story, market-rate buildings citywide, with a 2-story density boost for projects where at least 20 percent of the units were affordable.
In introducing the measure, Santana criticized what he characterized as outdated zoning “restrictions put in place over 50 years ago” that make it illegal to build triple-deckers on 58 percent of the city’s parcels.
‘The Perfect House in Boston’
Small multifamily buildings, he added, are a vital tool to helping families pool resources in order to become homeowners, and existing triple-deckers are popular with the city’s immigrant communities and communities of color.
Durkan argued that re-legalizing triple-deckers will aid in “creating more homes and more chances for people to build a life here,” and called the building type one of Boston’s two “iconic” forms, alongside brick rowhouses.
Pepén called triple-deckers “the perfect way of what a house looks like in the city of Boston” and praised the diversity they represent.
“I actually grew up in a triple-decker. A Dominican family on the first floor, a Jamaican family on the second floor and a Trinidadian family on the third floor. That’s the epitome of what a triple-decker is in Boston,” he said.
Responding to a design competition on small-scale affordable housing prototypes, Athena Real Estate Development’s “Triple-Quadra-Decker” prototype included 12 condominiums built using modular construction techniques, but fell $300,000 per unit short of feasibility. Image courtesy of Hacin + Associates, Kaplan Construction and Athena Real Estate Development
Affordability, Abutters Could Be Flashpoints
While the motion passed unanimously, Wednesday’s council meeting also laid bare some of the faultlines that could make this modest upzoning hard to pull off citywide: neighborhood input and affordability.
With traditional construction methods and Boston’s high land prices, it’s hard for new triple-deckers to pencil in many areas, especially on lots where such a project needs zoning relief due to setbacks, space for parking or height – a process that can turn contentious as neighbors jump in to voice objections to change.
“New housing should come with solid benefits – open space, safe streets and a voice for people who live nearby,” Durkan said in her remarks to her colleagues.
East Boston Councilor Gabriela Coletta Zapata urged her colleagues to find ways to make sure neighborhood residents can afford to make use of any upzoning that comes out of the push to legalize triple-deckers.
“What we have seen in the past and why I think this is so important, developers have utilized the zoning code to game the system, to build up to the necessary affordability requirement. It has been devastating in East Boston,” she said.
Requirements Hard to Pencil
Boston’s requirement that effectively 20 percent of a new building’s units be affordable kicks in when a proposed building contains seven units or more. Developers say that requirement makes small-scale multifamily buildings financially impossible in many cases.
One compromise, Coletta Zapata suggested, was a city-backed program with construction loans and design help for residents who want to build in their neighborhoods.
A joint city-Boston Society for Architecture design competition in 2023 tried to find ways to build triple-deckers with high affordability requirements never produced any units after none of the designs could bridge the gap between construction costs and either rents or purchase prices. One that used modular construction techniques still fell $300,000 per unit short, even if the city made the land available essentially for free, Banker & Tradesman reported at the time.
Many of the small multifamily buildings underway as part of the city’s “Welcome Home, Boston” program to build on vacant, city-owned lots rely on a limited pool of subsidies for financing.
