Kimball, Neb. ? The underground home of Don and Charlene Zwonitzer makes duct tape and plastic sheeting seem like the first little pig’s house of straw.

The Zwonitzers figure they could hold out a year without having to leave their home in an Atlas E missile silo.

“Maybe longer than that,” said Don Zwonitzer, 55, a retired electrical engineer. “The two of us could live longer than that. But we would probably open up our doors to everyone we can.”

While it may seem an improbable castle, the Zwonitzers are not alone. As many as a dozen of the nation’s former inter-continental ballistic missile silos have been turned into homes, says Ed Peden, who lives in an Atlas E silo outside Dover, Kan., and helps sell the sites.

Built in 1960, the silos not only cradled the most powerful weapon of the time, they were designed to withstand a 1-megaton blast a mile away. The Zwonitzers have topped that off with a nuclear-biological-chemical air filtration system; generators, solar panels and a wind turbine; a mostly underground greenhouse; fish ponds; and stockpiles of food.

Most silo-dwellers say the principal attraction is owning an unusual historic site and having the space of a mansion — 15,000 square feet — with low maintenance costs. Its security system is considered a plus.

Peden said the silos provide security against the elements, as well.

“Tornadoes don’t blow it away, termites don’t eat into it,” Peden said. “It’s going to be here for centuries. I like putting my energy into that kind of project.”