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Kendall Square Lab Space Refills Before It Becomes Housing — featured analysis graphic
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Kendall Square Lab Space Refills Before It Becomes Housing

Anthropic just leased 24,000 sq. ft. at One Kendall Square. Cambridge's lab glut is real, but the best located half re-leases before it can be housing.

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Thirteen homes changed hands last year in the ZIP code Anthropic just leased into. All thirteen were in two buildings. Both buildings opened in 1989.

That is 02142, Kendall Square, the densest concentration of lab and office square footage in the country, and over the twelve months ending August 31 it produced thirteen closed residential sales out of 719 across Cambridge. Not one of them was built in this century. Zero closings of anything built since 2023. I pulled those numbers myself out of MLS PIN because no public tracker slices that small, and they are the cleanest answer I have found to the question buyers keep asking me.

The question is some version of this: Cambridge lab vacancy is at a record, developers are giving space back, so is the glut finally going to loosen up housing near Kendall Square? It is a reasonable thing to assume. Every office-to-residential conversion story this year has trained people to read an empty commercial building as a housing unit in waiting. And on September 9, Anthropic signed a 24,000 square foot lease at One Kendall Square and showed why the assumption is only half right.

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Thirteen Sales, Two Buildings, Both Finished in 1989

Start with what the Kendall Square housing market actually is, because most people arguing about it have never looked. Here is every residential closing recorded in 02142 between September 1, 2025 and August 31, 2026. Not a top ten. All of them.

Every home sale in Kendall Square, 02142
Closed Sept 1, 2025 through Aug 31, 2026. MLS PIN, compiled by BMN Boston.
Address Built Price $/sf Days % of ask
75-83 Cambridge Pkwy E902 1989 $2,980,000 $1,560 207 81.6%
75-83 Cambridge Pkwy W702 1989 $2,900,000 $1,499 231 89.9%
75-83 Cambridge Pkwy 303 1989 $2,350,000 $1,774 329 87.7%
75-83 Cambridge Pkwy E1202 1989 $2,200,000 $1,397 132 88.2%
75-83 Cambridge Pkwy W1003 1989 $2,140,000 $1,342 74 93.9%
75-83 Cambridge Pkwy 203 1989 $1,995,000 $1,500 64 100.0%
75-83 Cambridge Pkwy E807 1989 $1,790,000 $1,105 225 94.2%
10 Rogers St PH19 1989 $997,500 $683 25 99.8%
10 Rogers St 606 1989 $991,000 $776 106 99.6%
10 Rogers St 308 1989 $850,000 $735 148 77.3%
10 Rogers St 415 1989 $809,000 $753 35 101.3%
10 Rogers St 213 1989 $790,000 $809 93 90.3%
10 Rogers St 703 1989 $730,000 $846 73 93.7%
13 sales, 2 addresses both 1989 median $1,790,000 $1,137 avg median 106 92.1% avg

Two buildings on the Lechmere Canal, both delivered a year before CambridgeSide opened across the water. The rest of Cambridge closed at 99.3 to 101.5 percent of the original asking price depending on the ZIP. Kendall Square closed at 92.1 percent and sat a median 106 days. That is not a hot market and it is not a cold one. It is barely a market at all, because there is almost nothing there to trade.

So when somebody tells you the lab glut is going to fix housing supply near Kendall, ask them which buildings. The honest answer right now is two, and they were finished when the first Bush was president.

What Anthropic Signed, and What It Did Not Ask For

On September 9 Anthropic announced a lease for 24,000 square feet across two floors at One Kendall Square, the office, lab and retail complex on Binney Street that Alexandria Real Estate Equities bought from DivcoWest in 2016 for $725 million. The company has been running a roughly 50 person local team out of a WeWork in Central Square. The new space holds 120 workstations. Move in is early 2027.

Two details matter more than the square footage. The first is that Anthropic told the Boston Globe it is not seeking any state or local tax break for the expansion. In a state where nearly every corporate headcount announcement comes bundled with an incentive package, a company more than doubling its local footprint and declining to ask is a signal about how badly it wants the address.

The second is the landlord’s own occupancy. Banker & Tradesman reported the Alexandria campus at One Kendall Square finished the second quarter 86 percent occupied. Hold that against a Greater Boston lab market that CBRE put at 28.7 percent vacant in Q2 2026, up 250 basis points year over year from 26.2 percent. The record everyone quotes, 28.0 percent, was set in Q4 2025 and has already been broken twice since. Meanwhile the trophy Kendall campus is running at 14 percent vacancy. Same city. Same quarter. Half the emptiness.

The Vacancy Rate Is an Average of Two Markets

This is the part that gets lost. A metro vacancy rate is a weighted average, and Cambridge’s lab inventory splits into three submarkets that behave nothing alike. Lincoln Property Company’s Q2 2026 lab report breaks them out.

Cambridge lab submarkets, Q2 2026
Direct vacancy, with quarterly leasing activity beside it. Lincoln Property Company.
East Cambridge · Kendall Square · 13.4M sq. ft.
13.4% vacant
947,110 sq. ft. leased in Q2. 19.3% available. Asking $89.50 NNN.
Mid Cambridge · Central Sq. and Lansdowne St. · 4.9M sq. ft.
15.5% vacant
76,950 sq. ft. leased. 36.3% available, because 20.4% of the submarket is on the sublease market.
West Cambridge · Alewife and Fresh Pond · 2.1M sq. ft.
39.5% vacant
10,402 sq. ft. leased in Q2. 49.8% available. Asking $71.15 NNN, the cheapest lab rent in the city.
LPC’s own Cambridge total line reads 22.8% vacant, which does not reconcile to the weighted average of the three submarket rows above. I am quoting the submarket rows, which the report states twice, in its table and in its narrative. For the metro headline I use CBRE.

Look at the leasing column rather than the vacancy column. East Cambridge did 947,110 square feet of leasing in a single quarter. West Cambridge did 10,402. That is a ninety to one ratio between submarkets whose inventories differ by six to one. Sanofi alone accounted for most of the East Cambridge number with a ten year, 900,000 square foot extension at 350 and 450 Water Street, which is itself the point: when a large tenant recommits in Greater Boston right now, it recommits in Kendall.

Two more things worth understanding before you read another vacancy headline. Vacancy counts space nobody occupies. Availability counts space you could lease, including space a tenant is still paying for and trying to hand off. Mid Cambridge is 15.5 percent vacant and 36.3 percent available, and the gap is almost entirely sublease inventory. That distinction is why the same market can look like a disaster or a soft patch depending on which number an article picked.

Takeda Is Not Giving Back Kendall Square

The biggest give back in the market is the one people cite most loosely. In February, Takeda put roughly 630,000 square feet on the Cambridge sublease market across 35 Lansdowne Street, 40 Lansdowne Street and 300 Massachusetts Avenue, plus about 125,000 square feet at 75-125 Binney Street, as Bisnow reported. Headlines called it a retreat.

It is a consolidation. Takeda signed a fifteen year lease in 2022 on 585 Third Street, a roughly 650,000 square foot BioMed Realty development in Kendall Square that delivers in the second half of this year, and it is pulling its scattered legacy space into that one campus. The company’s Cambridge footprint goes from about 1.56 million square feet across seven buildings to roughly 1.43 million across four. The net reduction is on the order of 130,000 square feet. The gross number that made the headlines is more than four times that.

And notice the addresses. Lansdowne Street and 300 Mass Ave are Mid Cambridge. The space Takeda is keeping is Kendall. This is the entire pattern in one tenant: legacy, off-core, older buildings go back to the market, and the best located square footage gets held or re-signed. AstraZeneca is doing a version of the same thing at 290 Binney Street, a 570,000 square foot anchored delivery landing this half. Neither of those buildings is ever going to be an apartment.

AI Leasing Is Already Bigger Than Cambridge’s Vacant Lab

Anthropic’s 24,000 square feet is small on its own. It is not small as a data point, because it lands inside a trend CBRE has been measuring for a while. In its 2026 Tech Gateway Office Markets report, CBRE totals cumulative AI company leasing from 2019 through the first quarter of this year by market.

Cumulative AI leasing, 2019 through Q1 2026
Millions of square feet. CBRE. Boston includes downtown and Cambridge office and R&D.
10.6
10.4
4.0
3.7
<1.9
<1.9
San
Francisco
Silicon
Valley
Manhattan
Boston
Seattle
London
For scale: adding up Cambridge’s three lab submarkets gives roughly 3.4 million square feet actually vacant today. Greater Boston’s AI tenants have signed for more than that since 2019.

Boston is fourth at 3.7 million square feet, behind only the two Bay Area markets and Manhattan. Tech’s share of all United States office leasing hit 22.7 percent in the first quarter of 2026, up from 15.3 percent a year earlier and from a cyclical low of 12.7 percent in 2023. Nationally that is a story about office. In Cambridge it is a story about lab, because in Kendall Square the two are the same buildings with different mechanical systems.

The local roster is filling in. AI Proteins took 40,000 square feet at Related Beal’s One Kenmore Square in January for its headquarters. Lovable took 6,000 downtown at One Lincoln. LabCentral turned vacant space at 700 Main Street into an AI BioHub for artificial intelligence focused biotech startups instead of waiting for a traditional lab tenant. In February the Healey administration announced a state partnership with OpenAI alongside the launch of the Massachusetts AI Coalition. None of those are conversions to housing. All of them are square footage coming off the table.

Nine Days in September

I do not usually get to make an argument with a calendar. This month I can.

September 2026, Cambridge
SEPT
9
Anthropic signs at One Kendall Square
24,000 sq. ft., two floors, 120 workstations, occupancy early 2027. No hearing. No public process. No tax break requested.
SEPT
16
Council committees vote to tighten the housing ordinance
Side setbacks from 10 to 15 feet, permeable open space from 15% to 20%, large unit buildings capped at three stories. Full Council votes September 28.
SEPT
17
Planning Board approves Cambridge Point at Alewife
4.6 million sq. ft. on 46 acres, 2,300 homes, 2.6 million sq. ft. of lab and office. Five years from land assembly to approval. Ten years to build in two phases.

One of those three things required a signature. The other two required a moratorium, a working group, a rezoning, a Planning Board, and a City Council that is still amending the rules nineteen months after passing them. That asymmetry is the whole argument, and it did not need a theory to demonstrate it. It happened in nine days.

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The Housing Is Going Three Miles Away

Cambridge is building. It is just not building where the lab market is tightest.

Every meaningful lab to housing pivot in this city has landed in West Cambridge, the 39.5 percent vacancy submarket out by Alewife and Fresh Pond. Boylston Properties swapped lab plans at 745 Concord Avenue for a residential tower. Toll Brothers and PGIM opened The Laurent at 55 Wheeler Street in June 2024, 525 units a ten minute walk from Alewife station. And on September 17 the Planning Board approved Healthpeak’s Cambridge Point, 4.6 million square feet on 46 acres in the Alewife Quadrangle with more than 2,300 homes, a project that began when Healthpeak spent $625 million assembling land, got frozen by the city’s 2022 moratorium on Alewife lab and office development, waited out a rezoning the Council finalized in September 2023, and only now has an approval.

One Kendall Square to Alewife station is about 3.3 miles as the crow flies. In Cambridge terms that is a different city. It is also the correct outcome, which is the part I want to be fair about. The Quadrangle has large parcels, surface parking, a subway terminus and a zoning framework that now requires housing alongside large commercial development. Andrew Copelotti of Boylston Properties put it plainly to Banker & Tradesman in 2024: “Thank God the moratorium came along. We’d have a built or half-built life science building in a tough market.” He is right. That space should be housing.

But read the Cambridge Point approval conditions and you find the sequencing problem in black and white. The pedestrian bridge connecting the project to Alewife station is required to start construction when 50 percent of the commercial portion is complete. The housing’s transit connection is gated on the lab and office space getting built first.

Housing Is the Only Bidder That Has to Ask Permission

Here is the mechanism, stated as plainly as I can.

When a well located lab or office building empties out, two kinds of capital look at it. One is a tenant with a signed term sheet who can be in the building in six months and who is bidding a rent number. The other is a residential developer whose bid is contingent on a zoning change, a permit, a financing, a construction cycle and, in Cambridge, a Planning Board. The first bidder closes in weeks. The second closes in years, if at all.

Landlords are not choosing housing over lab or lab over housing on ideology. They are choosing certainty. And because a discounted trophy rent still underwrites better than a residential redevelopment pro forma with five years of entitlement risk in front of it, the well located square footage clears to the faster bidder every time. Cambridge asking rents have fallen hard, from roughly $113 per square foot triple net at the Q3 2021 peak to $85.34 in Q2 2026, about 24 percent. A 24 percent haircut on Kendall rent is still a number a housing developer cannot outbid.

That leaves conversion to the buildings nobody is bidding on. Obsolete floor plates. Bad transit. Wrong block. Those are genuine candidates, and Boston has been working that problem with its own downtown conversion program, which I wrote about when the lab glut mostly got skipped by the conversion pipeline. The uncomfortable part is that the buildings that clear the conversion test are usually the ones you would least want to live near a job in.

The Conversion Math, Honestly

Let me put real numbers on the hope, because the hope is not crazy, it is just smaller than people think.

If every vacant square foot converted tomorrow
3.4M
sq. ft. of Cambridge lab actually vacant across all three submarkets
820K
of that sits in West Cambridge, the only submarket where conversion pencils
~750
homes that would yield at roughly 1,100 gross sq. ft. per unit
250-300
homes a year the city projects from its citywide upzoning
Roughly 750 homes is two and a half years of Cambridge’s projected production from the largest zoning reform in its history. It is real. It is not a supply valve.

And that top line assumes conversion is even physically possible, which for purpose built lab it usually is not, and assumes the 2.6 million vacant square feet outside West Cambridge would be available, which the leasing data says it will not be.

Set that against what the city has actually produced. Cambridge legalized multifamily housing citywide on February 10, 2025, ending single family zoning and allowing four stories by right with a two story bonus for inclusionary units on larger lots. It was a genuine landmark. In the twelve months that followed, the city permitted fifty smaller developments and zero large scale projects, up from 43 buildings in 2024. Vice Mayor Burhan Azeem’s assessment was blunt: “we’ve not actually seen any of these buildings actually open yet.” Then on September 16 two Council committees voted to add setbacks and open space requirements back on top.

What the Sales Data Says About Buying in Cambridge Right Now

None of the above has loosened anything, and the closing record shows it. Here is what Cambridge did over the last twelve months, by ZIP, straight out of MLS PIN.

Cambridge closed sales by ZIP
Sept 1, 2025 through Aug 31, 2026. 719 closings. MLS PIN, compiled by BMN Boston.
ZIP Area Sales Avg price $/sf % of ask Built 2023+
02138 Harvard Sq., North Cambridge 262 $1,978,877 $965 99.3% 9
02139 Central Sq., Cambridgeport 222 $1,427,741 $933 100.9% 11
02140 Porter Sq., Alewife 122 $1,639,780 $879 101.5% 9
02141 East Cambridge 100 $1,226,015 $860 97.5% 5
02142 Kendall Square 13 $1,655,577 $1,137 92.1% 0
Residential and residential income property types. Two additional rows carried Cambridge as the city with out of area ZIP codes and were excluded as data errors. Thirty-four Cambridge closings were of homes built 2023 or later, averaging $2,580,117.

Kendall Square carries the highest price per square foot in the city, $1,137, and 1.8 percent of the sales. Cambridge’s newest housing, the 34 closings of homes built since 2023, averaged $2,580,117. Whatever the lab market is doing, it is not putting downward pressure on any of that. There are 209 active listings in Cambridge as I write this, averaging $1.9 million, with 62 more pending.

What I Would Actually Do With This

If you are buying in Cambridge, stop underwriting a future supply wave that is not coming to your block. The vacancy headline is real and it is describing buildings you will never live in. Price the neighborhood you want on its own closing record, and in East Cambridge that record says 100 sales a year at $860 a foot and 97.5 percent of ask, which is a normal, competitive market with no glut discount in it.

If you are investing, the split is the opportunity. West Cambridge is where the basis is cheapest, the rezoning is done, the entitlement risk is now proven survivable, and the Cambridge Point approval just established what 46 acres of the Quadrangle is worth. That is a ten year story with real execution risk and it is the only part of Cambridge where the lab glut converts into housing at scale. East Cambridge is a different trade entirely. You are buying scarcity next to an employment base that is currently being rebuilt by tenants with more capital than the biotechs they are replacing.

If you own near Kendall already, the Anthropic lease is good news and it is not the kind of good news that shows up next quarter. A 120 workstation office does not move a housing market. A hundred of them would, and the direction of travel is the thing to watch, not the size of any one signature.

What I would watch next: whether any AI tenant takes a full building in Kendall rather than two floors, whether Takeda’s Lansdowne Street space finds a subtenant or sits, and what the full City Council does on September 28 with the setback amendments. If Cambridge tightens its own housing ordinance in the same month it approves 2.6 million square feet of new commercial space at Alewife, that tells you which bidder this city is actually set up to serve.

Related reading

We track Cambridge closings by ZIP and by submarket every month, including the cuts in this article, because the published town-level numbers are too coarse to price a specific block. If you are weighing a purchase near Kendall, Central or Alewife and want the real closing record for that pocket rather than a citywide average, reach out and I will pull it for you. If you already own in Cambridge and want to know what the last twelve months did to your number, start with a home value estimate.

Sources

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