Home Improvement

Saving the iconic New England three-decker from fire and bulldozers

How architects and construction experts are mitigating the fire danger in New England’s ubiquitous three-decker homes.

Merge Architects’ award-winning design calls for the addition of a 1,100-square-foot, three-story unit off the back. Rendering by Merge Architects

As city leaders and architects across New England consider ways to reinvigorate the three-decker, others are weighing in on why they fell out of favor — and how to improve them even without a costly renovation.

From South Boston to Fall River, and even on the silver screen in Boston-based films like “Spotlight,’’ “Good Will Hunting,’’ and “The Departed,’’ the three-decker remains an iconic housing stock. Think of it as the original form of affordable housing: Relatives would often live in each of the three residences that comprise the relatively inexpensive-to-develop building, or they might even rent one out for income. “Living in or near a New England triple decker,’’ the New York Times wrote, “was like despising the Yankees or skipping work on St. Patrick’s Day.’’


But the three-decker, like most legends, was not without its share of bad press.

Wealthier members of New England society looked down on the affordability it offered. The building was a symbol of anti-immigrant sentiment, and Providence Magazine even labeled it the “three-decker menace’’ in a 1917 article. “Massachusetts in 1912 passed a law allowing cities and towns to ban triple deckers. Not in so many words, though,’’ the New England Historical Society reported. “The language said municipalities could prevent the construction of any ‘wooden tenement’ in which ‘cooking shall be done above the second floor.’ “

Some of the critique, like fire safety concerns around the structure’s balloon framing, is valid, experts say.

. – Ryan Huddle/Globe staff

“American expansion was so quick at the time that we had to build houses faster and cheaper,’’ said Bill Rainford, a preservation carpenter and author of the woodworking and preservation blog Rainford Restorations. “Balloon framing was an early attempt to do mass production.’’

Balloon framing, in which homes are built with long, continuous lumber, was among the most common ways to build a house in the late 1800s and early 1900s, when three-deckers were springing up across New England. The problem is these structures, which didn’t have as much insulation, offer an unobstructed path for fire to spread quickly from the ground all the way to the attic and roof.


“It’s a design flaw,’’ said Roger St. Martin, Fall River’s deputy fire chief. “Obviously, it was made that way for ease of construction.’’

A small basement fire can quickly turn into something deadly that consumes an entire building. Interconnected floor joists link to the open stud channel of the exterior walls in a balloon-framed building, providing another accelerated pathway in a fire.

“The fire can honeycomb in just a short period of time,’’ said Gary Bowker, a retired fire chief in both the Air Force and the city of Winfield, Kan., and an associate instructor with the Kansas Fire & Rescue Training Institute.

There are about 9,000 three-deckers in Boston. Roughly 4,000 three-deckers remain in Worcester and Fall River apiece, according to the New England Historical Society. St. Martin estimates as much as 60 percent of the structural fires he’s seen in Fall River involve balloon-framed construction.

The construction and architecture industries eventually phased out this type of building design. Today’s more common platform framing, in which there is a break between floors, addresses fire safety concerns. Some of the prior balloon frame issues aged out because larger trees became scarce.

. – Ryan Huddle/Globe staff

“Some of that criticism and critique may have been invalidated because of the realities coming about just on materials alone,’’ said Taylor Cain, director of Boston’s Housing Innovation Lab.


But there are still thousands of balloon-framed structures across the region — and not just three-deckers.

A 2014 brownstone fire on Beacon Street in the Back Bay resulted in two firefighters, Edward J. Walsh Jr. and Michael R. Kennedy, becoming trapped in the basement of the balloon-framed building and died. The building’s structure contributed to the fire’s rapid spread, which burned through the firefighters’ water hose, according to a city report. “[The balloon-framing] technique created open interior voids within the horizontal ceiling/floor assemblies and vertical stud bays extending from the basement to the attic. Additional voids were often created during renovations. These void spaces often lack proper fire stopping.’’

Two Worcester firefighters, Jon D. Davies Sr. and Christopher L. Roy, died while fighting fires in balloon-framed three-decker residences in 2011 and 2018, respectively. Firefighting is a highly dangerous job, but balloon framing exacerbates the risk. “You’re thinking you’re dealing with the fire in front of you and it heads straight up,’’ one firefighter told the Worcester Telegram after Roy’s death.

“One of the first things we’ll do to a balloon-framed building is check and make sure the fire isn’t in the basement,’’ said Jerry Knapp, a veteran firefighter and training officer at the Rockland County Fire Training Center in Pomona, N.Y. “The fire travels so quickly through the building, you have to get firefighters everywhere at once. That’s a challenge, especially as departments cut manpower and stations.’’


Despite the fire concerns the building method poses, many three-deckers are protected by various preservation lists in cities like Worcester, where they are viewed as an endangered building type. But those who live in a three-decker shouldn’t panic, experts said. There are a variety of ways to address balloon framing and other design shortcomings.

Fire stops between floors, common now in platform-framed buildings, are vital and can be created in a variety of ways to existing balloon-framed buildings. A fire block insulating foam sealant and even nominal lumber like a 2×4 nailed at various distances to break up the balloon framing help prevent a fire’s spread.

“The question of fire prevention is a big one, and we tried to address it as best as we can in the light-touch way that we did,’’ said Soo Jin Yoo, a senior associate at Merge Architects, who worked on the firm’s winning design for the Massachusetts Clean Energy Center’s Triple Decker Design Challenge. “If this becomes a project we are going to construct, we’d take another deep level of analysis.’’

The design competition called on architects to formulate a way to retrofit three-deckers into significantly more energy-efficient structures ahead of the Massachusetts goal to be carbon neutral by 2050, but fire safety reflected in many of the winning designs.

Merge’s design focused generally on exterior changes along with the addition of a three-story, single-unit in the back. But safety components like sprinklers in the new unit, as well as improving the back staircase to modern fire code were included. Other elements would be added if the proposal moved from concept to reality. “We would do the due diligence to make sure it’s safe,’’ Yoo added.


Zephyr Architects, another winning team, called for a variety of retrofits to address energy and fire safety concerns, such as new insulation treated with a fire retardant to prevent cooling and heating leakage.

Gut renovations of a three-decker provide the opportunity to add even more fire blocking to break up the exterior walls and retrofit flooring with more fire-resistant materials, said Tim Zeitler, a designer involved with Zephyr Architects’ proposal.

But renovations can easily cost well beyond $100,000 for even the more basic design changes. For those looking for more economical solutions, there are ways to introduce more fire safety to a three-decker, the fire experts interviewed said. Keep basements clean and items stored away from boilers. Check for faulty wiring. Even installing smart fire alarm systems can be an improvement for detecting blazes faster.

“Basic fire prevention isn’t the most exciting stuff, but it’s what makes or breaks people living or dying in a fire,’’ Knapp said.

View a “CliffNotes” version of the Merge proposal.

Cameron Sperance can be reached at [email protected]. Subscribe to the Globe’s free real estate newsletter — our weekly digest on buying, selling, and design — at pages.email.bostonglobe.com/AddressSignUp. Follow us on Facebook, Instagram, and Twitter @globehomes.


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