In a last-minute rescue, a Pennsylvania-based preservation group has swooped in to save a distinctive modern house in Minnetonka from teardown.

The house, which was designed in the 1960s by Frank Lloyd Wright Jr., an architect and son of renowned architect Frank Lloyd Wright, sits on 12 prime acres of land that are being developed into 13 luxury home sites. The city had already approved the demolition when a preservationist learned of the house and its pending fate.

Thomas Papinchak, CEO of Polymath Park, a Wright preservation destination in Acme, Pa., said he contacted the builder, Zehnder Homes, and arranged an immediate visit to see the house, Birdwing.

"I scrambled," Papinchak said, and was "impressed. It's a mesmerizing structure, with so many traits of Frank Lloyd Wright — the large prows, angles and overall plan." Within days Papinchak had struck a deal to save Birdwing from the wrecking ball. The builder agreed to donate the house to the nonprofit organization that oversees the park, and a crew is currently engaged in "architectural surgery," Papinchak said. Birdwing will be dismantled, packed into shipping containers and reassembled at the park where eventually it will be open for touring and overnight lodging.

The cost of the preservation will be hundreds of thousands of dollars, according to Papinchak, but it's an investment in the park's mission of preserving Frank Lloyd Wright's work. "Once they're gone, they're gone."

The sudden turn of events was welcome news to the Rupp family, who owned Birdwing and its surrounding estate, Birdsong, for more than four decades.

"We're really, really delighted!" said Sandra Rupp, who spent her teen years in the house and now lives in Florida. "It was such a nice surprise." The family had tried to sell the large estate for several years, but were not able to find a buyer interested in maintaining 12 acres of land and preserving the house. Her father, WCCO-TV media executive James Rupp, died in December, triggering the sale.

"My dad would be so happy," Sandra said. "He did love that home, its architecture and taking care of the property. We are happy Zehnder is developing that beautiful place and keeping the name [Bird Song]. And it's wonderful to be able to preserve the house."

The spacious 6,500-square-foot Birdwing has many distinctive features, according to Sandra Rupp, including expansive views of nature from every room, walls of stone, carved woodwork, "massive fireplaces," a copper roof and a copper hood in the kitchen. "It was a beautiful place to grow up."

A few Twin Cities members of Docomomo, a modernist preservation organization, had advocated for saving Birdwing. Frank Lloyd Wright Jr., known as Lloyd Wright, while not as famous as his father, was a well-regarded architect in his own right, especially in California where he did most of his work. He designed Birdwing for Charles and Marjorie Pihl, a daughter of Arthur Erickson, who co-founded the company that evolved into the Holiday gas station chain. The house was originally designed for a site in Edina, but built later, in 1965, in Minnetonka where more land and better views were available.

At Polymath Park, it will join four other vintage homes with Wright connections. Two were designed by a Frank Lloyd Wright apprentice, a third was designed by Wright for a site in Illinois, and the most recent addition is another house with Minnesota origins — Mäntylä, designed by Wright for the Lindholm family in Cloquet, Minn., which was reassembled at Polymath Park and opened to the public earlier this year.

When Birdwing is reassembled and opened at the park, "This will be the only public site offering tours of work by the father and the son," said Papinchak. "It's about preserving a legacy and educating the next generation of students."