The Conversion Gap

For two years, the office-conversion story was told as a zoning story. Downtown rules were written for commerce — ground-floor retail, parking minimums, use tables that never imagined a family living on the fourteenth floor — and so the fix was to change the rules. Boston did it with a program; Massachusetts moved to do it statewide — a bill the House passed would fold a streamlined conversion tool and about $50 million in grants into a larger economic-development law. Rezoning is the satisfying part of the job: it is legible, it photographs well, and it costs a city almost nothing.

It is also, by itself, not enough to make a building happen. Converting an office to apartments commonly costs more than putting up new housing from scratch, against residential rents that sit far below what the same floor earned as offices. Elevator cores in the wrong place, floor plates too deep for windows, facades that have to be opened for light — each is a line item, and together they decide whether a conversion ever pencils. Take the state's largest conversion, the former Fallon headquarters in downtown Worcester: turning it into 198 apartments took a roughly $51 million deal that only closed with about $7.6 million in state tax credits, a $3.6 million state bridge loan, and a fifteen-year city tax exemption. The rule change was the cheap part. The money was always the hard part.

Which is why the celebrated “pipeline” keeps outrunning the cranes. Boston's own numbers tell it plainly: at the program's December 2025 extension, 1,517 homes were lined up and about 251 were built or under construction, a single project finished. Construction has kept moving since — a 2026 Planning Department figure puts units under construction at about 306 across five projects — but still just one building, 281 Franklin Street's fifteen apartments, has actually been completed. Some of that gap is simply the clock — conversions are among the slowest builds in real estate, and a three-year schedule routinely stretches to five, so part of the 1,517 is early rather than stalled. But the trade press that cheers the trend names the deeper problem out loud: developers have flooded the program with proposals, and most remain stuck at the starting gate, waiting on financing that the rezoning did nothing to provide.

A city points to a rezoned tower and an announcement. The meeting record shows the subsidy ask, the financing that keeps most projects from breaking ground, and how few of the homes have opened their doors.

If public money is what closes the financing gap, then another question follows: what does the public get in return? The conversions that move all share the same feature — a public check large enough to make the math work. In Massachusetts that means the state's Housing Development Incentive Program, a new Commercial Conversion Tax Credit, local tax-increment exemptions, and, in Boston, the Chapter 121B abatements its councilors debated on the record. Subsidy is not a scandal; it is the mechanism. But once public money becomes the thing that makes a conversion possible, the terms get decided in financing memos and tax-credit awards, not in the room where residents thought they were approving “housing.”

And where the money actually lands, the affordable share turns thin. Boston's program counts 284 income-restricted units among its 1,517 announced — a bit under a fifth, though, like the unit totals, that is a figure set at announcement, not delivered homes. The projects that have actually penciled tell the sharper story: in Worcester, One Chestnut Place (now rebranded Altitude Worcester) — the state's largest conversion, carrying that $7.6 million in credits and the fifteen-year exemption — is 198 apartments, none of them affordable; a second Worcester conversion, the Menkiti Group's Clark Block, pencils in five affordable homes out of forty-eight. The public helps pay to make the math work; how much affordable housing it buys is negotiated one deal at a time, and in the marquee project it bought none.

None of this makes conversion a mistake. A city with a hollowed-out commercial tax base may be right to pay for anchors: a lit tower and a few hundred residents can genuinely restart a block, and only about a quarter of the country's offices are even convertible, so a city that lands a few projects is targeting the feasible ones, not failing at the rest. Nationally the trend is real and climbing — roughly 90,300 apartments in the conversion pipeline, up about a quarter in a year. The subsidy may be exactly what these buildings need.

The mistake is a different one: treating the vote as the achievement. Changing the rules is the part a council can finish in an afternoon, and it is the part that gets the headline; the money, the delivery, and the missing affordable units are settled later, somewhere the public rarely looks. The downtown-revival pitch is loud and the ledger is quiet. The honest question a resident might ask, watching the rezoning pass, is the one the record keeps answering: once the easy part is done, what exactly did the rezoning buy?