The Jemne Building, a snug little art deco structure in downtown St. Paul, has had a variety of identities since it was built by the Women's City Club in 1931.

It's been a focal point for St. Paul's female elite, an art museum and the office of an architecture firm.

Now, work is underway for its latest and perhaps most fitting incarnation: Headquarters for District Energy St. Paul and its subsidiary, Ever-Green Energy.

The entities are leaders in the sustainable energy movement and they have been seeking a permanent new home that would reflect their growing national reputation.

District Energy purchased the Jemne, 305 St. Peter St., in March for $1.7 million. This month, it is carrying out a $1.2 million retrofitting effort led by the Minneapolis office of Duluth-based LHB Architects and RJM Construction.

The commitment of buying its own office building was a big step for nonprofit District Energy, which in recent years has been working out of offices in the high-rise Landmark Towers just down the block.

As the builder and operator of St. Paul's downtown district heating and cooling system, it saw a rare opportunity in the Jemne Building, which was already on its system and, since 1998, had housed the office of Wold Architects and Engineers.

"Not only does the purchase make sense in a purely real estate investment way — with its great location and Mississippi River views along a quickly redeveloping stretch of Kellogg Boulevard — but it really fits who we are as an organization," Nina Axelson, a spokeswoman for District Energy, said. "What we're doing here is taking an old building and giving it a new life as a hallmark to energy efficiency and education about sustainable energy use. In that way, it's very fitting to what we're all about."

District Energy St. Paul was a pioneer in sustainable energy, established by Mayor George Latimer in 1983 as a response to the 1970s energy crisis. Sixty percent of the heating it provides to downtown buildings is derived from renewable sources.

In 1998, it launched Ever-Green, a for-profit subsidiary dedicated to expanding the St. Paul model to other places through consulting and management services. It's that growing part of the organization that prompted the search for a permanent home for around 35 office employees, Axelson said.

Listed on the National Register of Historic Places in 1982, the Jemne Building's irregular, zigzagging shape; smooth, curving facade of Mankato Kasota limestone, meticulously executed terrazzo floor patterns and elements of dark polished granite designed by the husband-and-wife team of Magnus and Elsa Jemne all powerfully evoke the early-1930s heyday of art deco.

But District Energy President and CEO Ken Smith envisions the Jemne as a modern showcase for advanced energy technologies. This, he reasoned, could be accomplished not only by retrofitting the building with latest efficiency techniques, but also by re-purposing one of its most interesting features, a large ground-floor auditorium, as an education and training hub for energy sustainability.

The room, which can seat 120, offers some of the clearest interior examples of the Jemnes' "Moderne" style. Its 30-foot ceiling is adorned with a striking light fixture by Minneapolis interior designer Frank Post. Its stage is framed by streamlined columns.

But overall, the current work is not a full-blown historical restoration but more of a "surgical renovation," LHB architect R. Bruce Cornwall said during a tour of the building this week.

"There are parts of the building we're choosing not to restore, either because they are too far gone or the return value on the investment makes it not worthwhile," he said. "The wooden floors are a good example of what we are doing. In some cases, such as in the auditorium, we discovered when we removed some of the newer flooring that original wood beneath was in really good shape and could be refinished."

Don Jacobson is a freelance writer based in St. Paul. He is the former editor of the Minneapolis/St. Paul Real Estate Journal.