Midcentury modern homes are developing cool cachet, thanks to TV's "Mad Men," Atomic Ranch magazine and the revival of the rambler.

But some architecturally significant modern houses in the Twin Cities are "on the edge" -- in foreclosure and in danger of being demolished, according to preservationists who are doing their best to save them.

Last fall, the Minnesota chapter of Docomomo (documentation and conservation of architecture from the modern movement) organized a tour of well-preserved midcentury modern dwellings. This spring, Docomomo has planned a series of home tours to spread the word and help save vintage modern homes that could be razed because of neglect and buyer perception.

The first such tour in March spotlighted the 1957 Duff House designed by noted Minnesota architects Elizabeth and Winston Close. The vacant bank-owned home, which was listed for $599,900, is in need of restoration and some repair work, said Karen Rue, Docomomo board member. But it sits on 5 acres on Lake Marion in Woodland and even has a large guest house.

"It's one of the best of the Close houses and a midcentury modern gem that trumpets the virtue of that era," said Gar Hargens, owner of Close Associates in Minneapolis. "The soaring wing-shaped roof is quite beautiful and structural."

The Closes, who founded the firm, used an innovative diamond-shaped grid in the efficient, streamlined home, Hargens added. The home also features a handsome stone fireplace and expansive glass windows for views of the lake.

The Close home and many others are worth saving and preserving, said Rue, an Edina Realty agent. She scours MLS home listings for unique modernist properties advertised as "tear down" or "bank-owned" and tries to connect them with the right buyer.

"Many of these homes either get torn down or remodeled, diminishing their architectural value," she said. "That's really sad."

Nate Anderson, a Docomomo member who is restoring his own midcentury modern home, said buyers shouldn't equate old with obsolete. "We want to educate professionals and the public in terms of thinking differently about these properties," he said. "These homes have living spaces that flow together, which is what people are asking for today. If you have an appreciation for design, look back to the homes that already exist."

Upcoming tours, including one on Thursday, will highlight homes and offer ideas on how to preserve modernist elements, while updating spaces for 21st-century living.

"We hope that someday Docomomo can buy and restore some of the endangered properties and put them back on the market," said Rue.

Lynn Underwood • 612-673-7619