A 1930s-era building in downtown Minneapolis could be headed to the wrecking ball after Hennepin County moves its offices out of it this spring.

Century Plaza, a four-story building that fills a full city block near the Minneapolis Convention Center, was built as Miller Vocational High School. The county is selling the building, with development proposals due next month.

“It’s kind of an exciting opportunity,” said Mike Sable, the county’s facility services director. “We’ve got a lot of interest in the site, especially because of its great location.”

Human services employees already are moving out of the nearly 300,000-square-foot building at 1101 3rd Av. S. By May, all offices will move to six service centers in the county — part of a $41 million project of decentralizing services, locating them near residents rather than keeping them downtown.

Proposals for the property, which measures nearly 3 acres, were due Tuesday, but the county extended the deadline by 30 days to give potential buyers more time. So far, Sable said, developers have expressed interest in both preserving or demolishing the building, which the county estimates would cost $3.5 million to $4 million.

County and city staffers will review proposals and send a recommendation to the County Board. The county hasn’t said how much the property is valued at, and there isn’t an asking price. According to documents, the high cost of renovation and Century Plaza’s proximity to the convention center makes it a “likely candidate” for redevelopment.

A consultant evaluated whether the property could be designated as a local landmark or put on the National Register of Historic Places and wrote in a report that the building’s integrity and alterations in the 1980s disqualify it for consideration.

But David Frank, Minneapolis’ director of economic policy and development, said building changes or demolition would need city approval. If a buyer opted to tear it down, the city would decide whether a hearing should be held at its Heritage Preservation Commission.

“We think there are cool things about it,” he said. “We like the look of the exterior.”

The building opened in 1932 with a Streamline Moderne design, the same as the Minneapolis Armory and Minneapolis Post Office. The Miller Vocational School — named after Mary Miller, the sister of early settlers who built the first house on the west bank of the Mississippi River — taught boys and girls trades such as nursing, dressmaking, typesetting and woodworking.

A 1941 Minneapolis Star Journal article said it was “one of the most modern vocational schools in the country” for its 2,300 students. It’s an “almost self-sufficient city,” and, “without leaving the building, you can eat, get any type of tonsorial treatment, any type of beauty service, have your shoes repaired or new ones made, have any type of clothing or millinery made.”

The school closed in 1976 and the building was sold in the 1980s. Hillcrest Development converted it into office and retail, and demolished a 1950s auditorium to build a parking garage. Original recessed windows were also removed.

Hennepin County bought the building in 1996. Since then, the county has studied turning it into a 1,000-room hotel. But the county decided not to spend money renovating the building, which it said had reached the end of its “functional life span.”

“It’s an inefficient office environment for us,” Sable said. “Whatever gets built there, I presume is going to be bigger and better than what is there now.”