The city of Rosemount has finished a $3 million expansion of its historic Steeple Center, an addition meant to preserve the past while providing a venue for arts activities and a home base for senior citizen programming.

The project is the latest step in city officials’ efforts to use the old St. Joseph’s church building, which it purchased in 2004, then refurbished and opened in 2010 as Steeple Center.

The 10,000-square-foot addition includes a two-story open lobby area, a catering kitchen, restrooms, three multipurpose rooms and a conference room. It was paid for with capital improvement funds and grants from the county and Metropolitan Council. SKB Environmental donated $400,000 to complete the upper level.

“The starting point of adding on there was we were really looking for a new home for our senior programs,” said Dwight Johnson, Rosemount city administrator. “They’ve had a fairly small windowless room in our community center … and we thought we could do better than that.”

Arts activities, organized by the Rosemount Area Arts Council (RAAC), also needed room, Johnson said, and more restrooms and a catering kitchen were necessary for when the center hosts a wedding or big event.

Churches are among the most common old buildings to be repurposed because they offer large assembly spaces, said Erin Hanafin Berg, preservation support manager for the Preservation Alliance. But it’s rare for a city to purchase a historic property and fund its renovation and continued use, Berg said.

“It’s a very admirable step for a city to recognize its value,” Berg said. “More often than not, it’s a nonprofit organization that has to be formed [to preserve an old building].”

In nearby Lakeville, city officials made a similar move, transforming All Saints Church into the Lakeville Area Arts Council building in 2001.

Rosemount officials celebrated both old and new spaces Monday night with an open house, attended by about 75 people. Many were part of community groups that will call the center home.

Rosemount Area Seniors organizes a variety of activities, from card games to crafts, which will all be held in one place now.

And the Steeple Center will host about 90 percent of RAAC events and classes, offered on topics like watercolor and knitting, said Jeanne Schwartz, former chair of the arts council, a volunteer-run nonprofit. The arts council received a $10,000 grant to start a new theater group for seniors, the Second Act Players. Forty-three people showed up at an informational meeting. “We’re just kicking it off now,” Schwartz said.

The new addition is connected to a senior living complex, the Rosemount, making it convenient for residents to participate in activities or just come by for coffee.

“What I see is the ability of our residents who live there to be very engaged with the community,” said Mark Applebaum, a developer with the Makado Group that worked on the 92-unit building. Empowering residents has been key from the start, he said.

Convenient transportation and proximity to the library led Gary Selander to move into the Rosemount, he said at Monday’s Steeple Center open house.

“I like to be able to get out, do things, build things,” he said.

Selander plans to check out classes and entertainment at the center. He’s already attended the church services held by a Christian group in the assembly hall on Sundays, he said.

Built in 1924, the Steeple Center is old and has its quirks, Schwartz said.

Even so, “I’d rather have it preserved with all of its little idiosyncrasies than to rip it down and build a whole new thing,” Schwartz said.