WATERTOWN — The owner of a 29-acre cluster of brick buildings that stored gunpowder in the 1830s, built cannons for World War I, and housed an Army materials lab in the 1950s, wants to reinvent the site as a 21st-century hub where innovators come to work and play.
Fast-growing health care software maker athenahealth Inc., which bought the Arsenal on the Charles for $168.5 million, has invited Governor Deval Patrick and other state and local officials to the nearly 200-year-old campus Wednesday to unveil a plan to transform it into New England’s answer to Silicon Valley’s signature technology office parks such as the Googleplex.
The company envisions about 150,000 square feet of new office space for athenahealth and other businesses, a glass-enclosed atrium expanding the building that houses the New Repertory Theatre to create more space for artists and performers, walking and bike paths connecting the campus to the nearby Charles River, outdoor meeting spaces, an Arsenal museum, landscaped parks, a farmers market, a beer garden, new restaurants, and “accelerator” space that athenahealth would set up to incubate smaller health information start-ups.
“I want good chefs, good beer, and entrepreneurs,” said athenahealth’s chief executive Jonathan Bush. “Rather than a sealed-off campus, we’re going to open the Arsenal up to the community as a public resource. And we’d like to fit it into the historic context. We want to foment the next industrial revolution by bringing openness into health care.”
The plan will require zoning changes and other approvals from the town of Watertown to add height to existing structures and build walkways between some buildings.
It also may require state approval to alter historic structures.
“Obviously, these are historic buildings, and they’ll have to work through the approvals for their designs,” said state housing and economic development secretary Greg Bialecki.
Bush recently teamed up with Boston developer Boylston Properties and Boston retail management firm Wilder Cos. to buy three adjacent properties, including the 225,000-square-foot Arsenal Mall, with plans to develop housing and upscale shopping for young professionals. While that is a separate project from athenahealth’s plans for the Arsenal on the Charles, Bush and his associates say the two developments could advance in tandem as the Boston area’s high-tech and medical technology sectors spread outward from Cambridge’s Kendall Square.
But whether a new innovation cluster can sprout in a scruffy section of Watertown remains an open question.
At the least, planned improvements to the Arsenal office park could raise athenahealth’s profile for prospective employees and accommodate the company’s anticipated expansion.
Athenahealth is a leading vendor of electronic health record services to doctors and other medical professionals.
In June, the state Economic Assistance Coordinating Council granted athenahealth $9.5 million in tax credits in exchange for a promise to add 1,900 jobs over the coming decade at the Arsenal.
The company currently has more than 1,100 employees at its headquarters and research center on the site.
As it expands, athenahealth will gradually take over space now leased at the Arsenal by 20 other tenants, ranging from Netwatch Systems to Envivo Pharmaceuticals to Harvard Business School Publishing.
Bialecki said state officials view the move as part of a potential doubling of the Massachusetts innovation economy over the coming decade, with business activity “getting distributed around Greater Boston” to areas such as Watertown, Quincy Center, and Assembly Square in Somerville.
Athenahealth hopes to break ground within nine months, but estimates it could take five years to complete all the work. The company’s executive offices would move to an expanded structure on top of the complex’s current parking garage that would also include business development offices, an executive briefing center, and a roof garden.
A second parking garage would be built on the edge of the campus, allowing athenahealth to remove asphalt parking lots around the Arsenal to create more parks, gardens, and green spaces.
In addition, a new filtering system will re-create channels known as swales throughout the campus, removing impurities from storm water before it drains into the river.
“We want to bring the river to Watertown, and bring Watertown to the river,” said landscape architect Glen Valentine, senior associate at Stephen Stimson Associates in Cambridge.
Valentine said the project’s planners hope to plant native shrubs such as red twig dogwoods and attract wildlife such as turtles, butterflies, hawks, and red-wing blackbirds.
The new museum, along with decorative cannons around the complex, will highlight the Arsenal’s storied past.
“There are so many people in this town who have a family history with the Arsenal,” said Carolyn Rickman, an athenahealth vice president who is one of the project’s leaders.
Originally located in Charlestown, the Arsenal was moved to Watertown in 1816 as military leaders sought a site physically protected from seaborne attack, said historian Robert Damon, the Wellesley Historical Society executive director who is consulting with athenahealth on the project.
Damon said the buildings on the parcel originally warehoused muskets, cannonballs, and gunpowder, but began manufacturing cannons and the carriages that held them in the 1830s.
During World War I, when it built larger cannons, the Arsenal became a pioneer in metallurgical technology — such as gauging the strength of metals — a role it expanded after World War II as an Army materials research center. The Army closed the Arsenal in 1986.
“We hear a lot about innovation hubs these days. That spirit of innovation has been here for a long time,” Damon said.
In preparing for the makeover, Somerville architect Charles Rose said he is aiming for a post-industrial feel that can attract the “hacker chic” crowd.
Rose said he visited other distinctive information technology campuses, including Google’s and Apple’s. While those Silicon Valley sites have quirky energy, Rose said, he concluded they were too “inwardly focused campuses impermeable” to outsiders.
By contrast, Rose said, “athena’s vision is an incredibly civic-minded one. We’re creating a campus that doesn’t pretend to be part of the city. It is part of the city.”Robert Weisman can be reached at firstname.lastname@example.org. Follow him on Twitter @GlobeRobW.