Waterford — Charter Oak Federal Credit Union, now based in Groton, has gained the local approvals it needs to build an $18 million complex here on Route 85.

Groundbreaking for the 65,000-square-foot project is set to begin this fall, with construction to be completed by late next year, Brian Orenstein, Charter Oak's chief executive officer, said Thursday.

When finished, the four-story building at 1055 Hartford Turnpike will house Charter Oak's headquarters as well as its 13th branch office and a 200-seat "community room" that will be available to the region's nonprofit and civic groups.

Orenstein called the project "a vote of confidence" in the region's economy.

"What this says about Charter Oak is that we are a strong financial institution that can afford this kind of investment in this economy," he said. "We're going to build as local as possible. We'll give local contractors every opportunity to bid on this project. ... When I say local, I mean New London and Windham counties — that's who we service."

Founded in 1939, Charter Oak had its best year ever in 2011, reporting record profits of $8.4 million. At the end of March, its assets totaled $731 million.

Charter Oak will consolidate its administrative functions at the new Waterford facility, where about 115 employees will work, including 10 new hires, Orenstein said. The other employees will transfer from existing Charter Oak offices in Groton, Niantic and Waterford. The rest of Charter Oak's 180 employees work at its 12 existing branches, all of which will remain open.

The credit union's current headquarters at 32 Chicago Ave. in Groton will continue as a branch location. The second floor, now occupied by headquarters staff, will be renovated for possible leasing.

"We've simply outgrown our Groton headquarters," Orenstein said.

Dan Steward, Waterford's first selectman, hailed the Charter Oak development in a press release, saying the credit union has been "a good and celebrated neighbor to all in our area." He called the community room "an excellent feature."

Orenstein said the room will be available free of charge to local groups and also could serve as a "banquet-type facility."

The new building has been designed by Point One Architects of Old Lyme. CLA Engineers of Norwich will provide engineering services, and Enterprise Builders of Newington will serve as the general contractor.

"It's sort of different-looking for New England, though we're keeping some New England flavor," Orenstein said of the structure's design. "We wanted it to be a signature building. ... We'd like it to be a destination of some type."

Waterford's Planning and Zoning Commission granted the last of the local approvals for the project this week. Earlier, the town's Utility Commission approved Charter Oak's plan to extend a sewer line along Route 85. The site is at the intersection of Industrial Drive and Route 85 and includes about 10 acres zoned for industrial development, according to Town Planner Mark Wujtewicz.

The site is south of the Waterford Speedbowl on Route 85.

b.hallenbeck@theday.com

By the numbers

What: Charter Oak Federal Credit Union's new headquarters

Where: 1055 Hartford Turnpike, Route 85, Waterford

Size: 64,796 square feet

Details: Four-story complex will house Charter Oak's 13th branch office, headquarters staff, a community room for nonprofit and civic groups, and a four-story glass atrium featuring a large architectural rendering of an oak tree, symbolizing Charter Oak's roots as a community-focused credit union.

Groundbreaking: This fall

Completion: Fall 2013