A 103-year-old office building in downtown Portland sold at auction Thursday morning for $1.6 million, about half what its former owner paid for it 10 years ago.

The sale was of the front half of 415 Congress St., which has about 50,000 square feet of office and retail space. The back half of the building, which is considered a separate parcel even though one roof covers both, is owned by the Masons and was not part of the sale.

The building was bought by Heather Ashby, who said she has long been involved in buying and renovating houses in Portland and recently decided to take on commercial real estate. She and her husband, Sheldon Ashby, who owns a real estate firm, said they will work with city and preservation officials to make sure the renovation of the building – built in 1911 and on the National Register of Historic Places – is done properly.

The Congress Street building, along with the Masonic Temple, was named one of the city’s “Places in Peril” by Greater Portland Landmarks in 2012.

Landmarks called it one of the finest examples of Beaux Arts architecture in Maine. The organization noted that the Masons’ original plan was to use lease and rental income from the commercial space in the front of the building to support the Masonic Temple. But the income stream declined. The building was split into two condominiums in 1989, and the front half was later sold.

Landmarks said the building’s exterior suffers from “extensive deferred maintenance.” The Masons set up a nonprofit organization in 2012 to raise money for maintenance and renovation of the fraternal organization’s half of the building.

The city has assessed the value of the front half, 415 Congress St., at nearly $3.5 million. The property last changed hands in 2004 for $3 million and, prior to that, it sold in 1996 for $1.5 million.

The building’s former owner, Kevin Mattson, said his firm, Dirigo Capital Advisors, recently bought the former MaineGeneral hospital buildings in Augusta. Those buildings are undergoing a $23 million redevelopment, he said, and his company wasn’t able to focus on that project and 415 Congress St.

Mattson told the Portland Press Herald last month that he decided to auction the building as a “gamble” to attract a higher price. He said he hoped to get more than the $3 million he had paid for the building a decade ago.

Attempts to contact Mattson after the auction were unsuccessful.

There were fewer than 10 bidders at the auction, which was held in a conference room on the fifth floor of 415 Congress St. Thomas W. Saturley, president of Tranzon Auction Properties, said the process took about an hour.

Ashby said she will try to lease out some of the open space in the building even as renovations are underway. She anticipates that the facade will require the most work.

According to the Tranzon property description, the first three floors of the six-story building are occupied, although about a quarter of the third floor is occupied by Mattson’s firm, which is headquartered in Hallowell.

The fourth, fifth and sixth floors are vacant, according to the Tranzon document, but part of that space had been occupied by a law firm until this year. Each of those floors has about 8,000 square feet of space.

Sheldon Ashby said he thought he and his wife got a bargain.

Even with the need for renovations, “I think at the price we snatched it up, we’ll make it work,” he said.