The New Face of Flex Development
This OpEd by Hunneman's Director of Research & Strategy, Mark Fallon, was originally published on Banker & Tradesman on July 26, 2026
Developers Lure Climatech and Advanced Manufacturing
The traditional flex/R&D inventory that is mostly well-known throughout the commonwealth is frequently defined as vintage, pre-2000-era product. It predominately consists of 2-story brick buildings, with 1,800 to 3,000 amps of power available.
This dynamic has fundamentally changed with the advent of a relatively nascent industry to Massachusetts: climatetech, energy tech, advanced manufacturing and robotics.
This rapidly growing industry has been further reinforced by the Mass Leads Act’s $1 billion investment, as well as a massive inflow of federal dollars. The CHIPS Act directs $280 billion in total spending, roughly $52 billion of which is earmarked for semiconductor manufacturing and R&D.
As a consequence, the Department of Defense selected Massachusetts as one of the eight existing microelectronics hubs in the country.
Private Equity Joining Government Funding
Furthermore, private equity and venture capital investment inflow continues to provide vital financial backing.
Per the Massachusetts Clean Energy Center, Massachusetts is the second-largest climate tech ecosystem in the country and ranks first in climate tech startups per capita. These users have now taken center stage as the new, predominant tenants in the market, and they require specialized assets to conduct their business well beyond what current inventory can provide.
These bespoke buildings command a significant rent premium, which attracts the interest of investors and developers alike.
Per Hunneman Research, rents for these new buildings are the highest of any industrial/flex product and come with outsized tenant improvement packages. Historically, tenants who have required this type of space have been forced to retrofit older, dated stock that is not a true representation of the space they need.
These new builds share several key characteristics: they usually have an RBA of under 200,000 square feet, adaptable layouts, dramatically enhanced electrical capacity (usually exceeding 6,000 amps at a minimum, and often rising to over 8,000 amps), and integration of laboratory, engineering and manufacturing functions.
Clear heights are important as well: Traditional flex inventory frequently runs lower than 20 feet, whereas this new generation of product runs at a minimum of 25 feet and can exceed 34 feet.
This is a critical component: while retrofitting is possible, it is extremely capital- and time-intensive to change this aspect of the physical infrastructure. These heights allow users to stack mechanical processes above the floor, creating room to install tall equipment (think: cranes, tanks and gantries), and make adjustments later.
A final necessity is column spacing. New buildings for this archetype command wide open spacing – 40-by-40, 40-by-60 –which allows for reconfigurable floors for equipment, process lines, and mezzanines.
Metro North Projects Test Market
44 Middlesex St. Image courtesy of Camber Development and Wheelock Street Capital
As evidence of the popularity of this burgeoning asset class, the proof is in the leasing and the construction.
The latest to break ground is 161 Concord Road, in Billerica, a Berkeley Investments project, developed through its new joint venture with Garbe (branded Berkeley Garbe). It is being built to the specifications discussed above, set to capture the needs of these users.
The 44 Middlesex Turnpike in Bedford, a Camber Development/Wheelock Street Capital asset was delivered in late 2024 and has since secured a sizable lease commitment from Fourth Power, a thermal energy storage company. They have plans to construct an adjacent building on the same site, with comparable characteristics.
King Street Properties has also capitalized on this trend: Pathway Devens has completed four buildings of its master campus and has met with significant success. Electric Hydrogen, a company that manufactures electrolyzer systems, committed to the entire 187,000-square-foot building at 33 Jackson Road, and Vulcan Forms, a digital manufacturing company that utilizes laser printing systems, leases the entire facility at 39 Jackson Road.
The demand is durable. The open question is whether power, land, and capital can deliver these buildings fast enough to meet it.
Mark Fallon is director of research & strategy at Hunneman.
