Boylston Properties’ 185,000-square-foot speculative industrial conversion Linx on Watertown’s Arsenal Street landed its first tenant with a 45,000-square-foot lease by Kendall Square life science startup C4 Therapeutics.

Demand for next-generation office space and life science R&D facilities is generating a wave of speculative redevelopments in Boston’s western suburbs and a string of recent success stories luring growing companies from Cambridge and elsewhere along the Route 128 belt.

Refreshed office space, speculative lab projects and office-to-lab conversions are driving development activity in the suburban market. And the strategy appears to be paying off: Boston suburbs tallied over 700,000 square feet of positive absorption year-to-date, according to Cushman & Wakefield’s latest MarketBeat report, rebounding from negative 500,000 square feet in the first half of 2016.

Repositioning projects such as shoemaker Clarks North America’s new headquarters at former Polaroid lab space in Waltham and Griffith Properties’ office-to-lab conversion at 275 Second Ave. in Waltham have dispelled the familiar narrative of thriving downtown markets and stagnant suburbs.

Following the departure of office tenant IBM Rational Software, Boston-based Griffith Properties received the bulk of interest from life science companies to fill a 100,000-square-foot office building at 20 Maguire Road in Lexington, which Griffith owns in a partnership with Walton Street Capital.

Griffith is seeking permits for a lab conversion project expected to be ready for tenants by mid-2017, Chief Investment Officer Marci Griffith Loeber said. The firm plans to market lab space in the high $30s per square foot on a triple-net basis, less than half of the going rate in the East Cambridge life science hub.

“We have a tremendous amount of interest in lab space both from the suburbs and Cambridge tenants,” Loeber said, citing the property’s location near Lexington’s Hartwell Avenue life science cluster.

Griffith is seeking to duplicate its recent success at 266 Second Ave. in Waltham, where it converted half of the 96,695-square-foot building into lab space in its role as operator on behalf of owner Rockwood Capital. Three lab tenants, including ImmuneXcite, filled the remaining space in less than a year, Loeber said, bringing it up to 100 percent occupancy in May. The property is under agreement to an undisclosed buyer, Loeber said.

From Industrial Space To R&D Chic

With only 36,000 square feet of lab space available in Cambridge’s Alewife submarket, according to Cushman & Wakefield research, developers are positioning East Watertown’s Arsenal Street corridor as the next life science relief valve to Kendall Square.

That was Boston-based Boylston Properties’ game plan for Linx, a former Verizon warehouse at 480 Arsenal St. converted and expanded into 185,000 square feet of creative office and lab space. The majority of tenant inquiries have come from East Cambridge, said Duncan Gratton, an executive director for Cushman & Wakefield which represents ownership.

Following the building shell’s completion in April, LINX landed its first commitment in C4 Therapeutics, a venture capital-backed startup that leased 45,000 square feet for occupancy in early 2018.

“Getting the first (lease) is huge from a momentum and credibility perspective. Our goal from day one was to get a quality Kendall Square life science firm,” Gratton said.

In Lexington, Boston Properties is modernizing its 158,900-square-foot 191 Spring St. office building following last year’s departure of shoemaker Wolverine Worldwide for 10 Citypoint, a build-to-suit office building in Waltham.

Mimecast, a rapidly expanding email cloud storage provider, leased 80,000 square feet at 191 Spring St. after outgrowing its offices at Riverworks in Watertown, spokeswoman Alison Raymond Walsh confirmed. London-based Mimecast expects to have 300 employees in Lexington when it initially takes occupancy by year’s end. Although future hiring plans are undisclosed, the new offices are designed to accommodate up to 800 people, Walsh said.

“Landlords are taking some aspects of the ’80s-style buildings and turning it into something creative,” said Bill Lynch, a senior vice president at Colliers International Boston. “They’re opening up ceilings and adding polished concrete floors to get that creative setting in a traditional office building. So many buildings in the core (Route 128) market are doing it. It’s rare to find one that isn’t.”

And at 180 Wells Ave. in Newton, last month’s relocation of appliance maker SharkNinja to Normandy Real Estate Partners’ Founders Park redevelopment in Needham prompted the owner of SharkNinja’s former North American headquarters to hit refresh.

Intrum Corp. Real Estate Management and Development hired Elkus Manfredi Architects to design a new floor-to-ceiling glass curtain facade with illuminated decorative fins and new shared amenities, such as a central courtyard with firepits and seating for 70 people.

Intrum is counting on the updates to attract tenants to fill the existing 55,000-square-foot building as well as an adjacent 116,000-square-foot build-to-suit office building site.

Intrum President “Randy Goldberg would often say, ‘Why can’t suburban office parks be sexy and appealing and have multiple amenities that would appeal to the tenants out in the market?’” said Alex Plaisted, a first vice president at CBRE/New England who represents ownership in leasing. “He’s made an attempt to activate a site and an area that otherwise has been flat.”