What Does It Take to Build a Disaster-Proof House?

Ryan Runge, the president of Advanced Earthen Construction Technologies, who sold the couple their block-making machine, said the blocks are mold-proof and, when reinforced with rebar, earthquake-resistant. The walls are so thick that they retain heat in winter and remain cool enough in summer that air-conditioning isn’t necessary, at least on the first floor. “It’s like living in a cave,” Mr. Runge said.

But there’s a downside: Compressed earth block homes are labor-intensive to build and may not be any cheaper than wood-frame houses. The Phinizys’ home will cost a little over $150 a square foot — roughly in line with the estimates they got to build a conventional home.

As Mr. Phinizy put it: “It’s not all dirt cheap, so to speak.”

Earth blocks also weigh up to 40 pounds each, Mr. Runge said, which makes them difficult to transport in large quantities. Because of the high labor costs and low material cost, this construction method is more widely used in disaster-prone places like Haiti and Mexico, where labor is less expensive than in the United States, and on higher-end homes, whose owners can afford to pay more for labor and hire pricey structural engineers to help with the additional permitting. (Local building codes don’t usually account for earth-block construction, so a structural engineer has to sign off on these projects.)

But while it’s still a niche market — there are maybe a couple hundred earth-block homes in the United States — Mr. Runge said he has seen demand grow in the past year or so, as lumber costs have increased and natural disasters have taken a toll on housing.

For the first three years that he owned the company, Mr. Runge said he had about one house under construction every year. But this year, his fourth, there are five homes in the works. “We’re selling them faster than we can make them now,” he said of the earth-block-making machines.

On the waterfront in Florida, Gene and Tammy Tener are confronting a different kind of challenge.

The Teners bought a house in Crystal River in 2010, because of the area’s natural beauty. “We’ve got manatees that come right up to our dock, and dolphins that come up to the sea wall,” said Mr. Tener, a mechanical engineer. “For me, it was a dream come true.”