Margaret Humphrey had long admired the 1948 Allianz building in Minneapolis' Lowry Hill neighborhood for its flat-planed modern design and granite and limestone facade. So when she heard it was to be demolished to make room for the Walker Art Center addition, she procured the rights to remove some of the building's architectural salvage.

Humphrey's stash included commercial steel windows, 20 walnut doors, sheets of walnut paneling, massive slabs of granite, even the plith that held the company's famed bison sculpture. It sat in storage for a year until Humphrey found the perfect fit for all of it: a 1955 Prairie School home inspired by Frank Lloyd Wright.

"When I entered the front door, I knew it was the one," she said. "The materials that I had salvaged seemed to be made for the house."

The midcentury modern home, designed by local architect David Griswold, had strong geometric lines, an open floor plan and natural elements such as interior brick walls and fir-clad ceilings. It also boasted a prime location on about three acres of woods and wetlands in Dellwood.

But the house badly needed a renovation after "updates" in the 1970s and '80s.

"I wanted to reveal the home's original simple aesthetic," said Humphrey, who bought it in 2002.

Today the recycled materials are inside and outside the revamped 3,900-square-foot home. The steel windows frame panoramic wetland views and granite slabs form terraced stairs in the landscaping. Architect Tim Stefan, who designed the renovation, "took all these crazy elements and made sense of them," she said.

Contemporary spin

Humphrey collaborated with Stefan on the home's renovation with a goal of executing a contemporary take on midcentury design. She tore down the dark 1970s rec-room addition and built a new structure for a kitchen, family room and office off the back of the home. Its soaring roofline, 20 feet high at its peak, was designed to accommodate the oversized salvaged windows. The view includes Humphrey's Zen garden and reflecting pool.

"The new space continues the midcentury design concept of inviting nature in," she said.

Contemporary touches include a steel-cylinder fireplace and steel beams, which provide an edgy contrast to the wood beams in the rest of the home. "We wanted the addition to reflect this century, not the last century," Humphrey said.

In the original part of the one-story home, she gutted and remodeled spaces, including the living room, but was careful to retain elements that added to the home's period character, such as interior brick walls and golden-hued wood ceilings. In some of those rooms, she introduced remnants of the Allianz building -- salvaged walnut panels cover several walls and border some windows.

Beneath old laminate and carpet, Humphrey discovered concrete floors, a signature of Frank Lloyd Wright's design. She replaced the original concrete floors with poured concrete with in-floor heat, a must-have in Minnesota. "I love the play between the industrial concrete and the warmth of the wood," she said.

In the 2003 renovation, Humphrey spared no expense on many of the building materials, including the copper roof and siding on the addition. Now Humphrey, a violinist with the Minnesota Opera Orchestra and Belladonna Baroque Quartet, is moving back to the East Coast. She's listed the home for $849,900. And although she is unlikely to recoup what she spent on the renovation, she has no regrets. It was important to her to be able to recycle high-quality building materials and update a unique home so it could enjoyed for another generation.

"The process of working with the architect, builder and landscaper was such a joy." she said. "I learned a lot, but now I'm ready to let go and allow someone else to be the custodian of it."

Lynn Underwood • 612-673-7619

Laura Tiffany and Beth Lindahl-Urben of Coldwell Banker Burnet have the listing; 612-924-4386.