Boston explores converting office buildings into housing, but challenges abound

Just a relative handful of office buildings along State Street would be suitable for residential conversion, one design firm found.

An old six-story warehouse on Shawmut Avenue in the South End was converted into condominiums, with a seven-story addition above.David L. Ryan/Globe Staff

Years ago, walking into the low-slung old warehouse at the corner of Shawmut Avenue and Herald Street, you’d see a run-of-the-mill office. Today, the lobby is light and airy, with white marble, tan wood, and a library. Upstairs, newly developed condos stand both in the six-story red-brick warehouse and seven floors of new glass and metal that rise out of the building that’s more than a century old.

“I think a lot of people who saw that building in its original state — they didn’t really see it for what it was,” said Michael Liu, senior partner and design principal at The Architectural Team, which designed the converted property for The Davis Cos. “It wasn’t a Class A office space. It was kind of funky and probably thought of as being kind of drab.”

The 138-unit condominium building at 100 Shawmut opened this month, the latest example of office buildings being converted to housing.

The concept of reusing and converting space in Greater Boston, or indeed nationally, isn’t new. But it’s a post-pandemic priority for Boston Mayor Michelle Wu’s administration, which is aiming to inject some energy into a downtown core that’s still struggling with the realities of a workforce that’s no longer coming into the office five days a week.

The Boston Planning & Development Agency is interested as well. New BPDA director, Arthur Jemison, said in an e-mail that the agency “is exploring the feasibility, costs, and incentives of office to residential conversions as a solution to help increase housing supply in Downtown Boston.”

Design firm Gensler, which has studied the ins and outs of residential conversions across North America, recently studied some 84 commercial buildings in downtown Boston to gauge their suitability for conversion. Gensler has crafted its own scorecard ranking buildings on factors such as location, cost of conversion, and current vacancy rate.

Their findings indicate conversion may not be a large-scale solution.

A rooftop bar and deck at an old six-story warehouse-turned-office at 100 Shawmut Ave. in the South End. David L. Ryan/Globe Staff

Across North America, just three out of every 10 buildings Gensler has analyzed appear viable for potential conversion. In downtown Boston, that rate is even less: 10 of the 84 buildings Gensler studied — just shy of 12 percent — have a high enough score to warrant further review.

“That’s not a lot,” said Todd Dundon, a principal with Gensler in Boston. “But if one or two of those owners decided to make this change and actually go through with it, you’re now bringing a 24/7 audience to a neighborhood.”

The 84 buildings Gensler studied stretch along the State Street corridor from Government Center to the Rose Fitzgerald Kennedy Greenway, including mid-rise stone, brick, and concrete offices.

The Wu administration’s focus on reviving downtown comes as the city is still navigating the realities of a hybrid workforce. Finding ways to generate more activity downtown beyond traditional office workers — along with growing the number of residents in the area — has been key to the city’s downtown revitalization plan, said Segun Idowu, Wu’s chief of economic opportunity and inclusion.

“Every major city is rethinking the downtown core and its future,” Idowu said. “We cannot only rely on the workforce coming back to the office.”

Even before COVID, there were some office conversions. Eight buildings downtown were converted from office to residential from 2011 through 2017, according to a report by the Downtown Boston Improvement District. Combined, they added 190 units of housing. By comparison, Millennium Tower, when it opened in 2016, brought 442 condos to Downtown Crossing.

There are of course challenges to converting a building for residential use. Building proportions are key, and the layout of office floorplates often don’t lend themselves to residential use.

Apartments are typically 28 to 30 feet from the exterior wall into the unit, Liu said, with an interior corridor. So buildings with longer floorplates that would create very deep or very narrow units — “bowling alley units,” per Duanne Render of Gensler’s Toronto office — wouldn’t necessarily work.

Rooftop decks for general use at an old six-story warehouse-turned-office at 100 Shawmut Ave. David L. Ryan/Globe Staff

But the pivot toward working from home with more frequency could create a shift in what’s acceptable as a residential floorplate, with deeper units perhaps allowing for work from home space, Liu said.

“There may be a way that those sorts of conversions actually can accommodate a different way that people are living, which I think bodes well for what the mayor would like to encourage,” he said.

Buildings that have typically been converted in Greater Boston, Liu said, have been older, turn-of-the-century properties, such as three Ladder District buildings included in the Downtown BID report, at 37 Temple Place, 44 Winter St., and 6 Hamilton Place. What’s new in this latest push for office-to-residential conversions is looking at the feasibility of converting 1970s and 1980s-era offices, he said.

More of those younger buildings are finding it harder to lure tenants as the global commercial real estate industry faces headwinds unseen in decades. The gulf in demand between high-quality Class A office assets and lower-quality offices “perhaps has never been wider,” according to a 2023 global commercial real estate outlook from the Deloitte Center for Financial Services. Office owners have to consider making upgrades or conversions to their properties “or risk obsolescence,” the report said.

However, the report notes, while residential conversions across the US were considered “an early strategy to capitalize on rising residential rents and limited inventory,” they “proved difficult to implement.”

For the 10 buildings that ranked high enough on Gensler’s scorecard, the next step could be more study. How would the building’s layout contribute to a good mix of unit sizes? Where could amenities go? What about accessibility upgrades?

While 10 out of 84 isn’t a huge percentage, Dundon said, it could create other opportunity down the line.

“What that then could potentially mean is that the other 74 buildings could be repurposed for something else,” he said. “Single-use districts are not the future of cities.”