Elizabeth C. English holds four advanced degrees—including a PhD—in architecture, urban planning and engineering. She has taught at 10 institutions of higher learning. But after more than six years, she still hasn't been able to get her solution for amphibious flood-resistant buildings off the ground—at least in the U.S.
The barrier is that amphibious houses with buoyant, boat-like foundations sit on dry land most of the time. In a flood, they float, rising in place along stationary guide posts. In the U.S., houses that rise and fall with flooding are not eligible for inexpensive National Flood Insurance because they do not meet the requirements for permanent static elevation above the zone's base flood elevation.
Undaunted, English is pushing for a reinterpretation of the statutes of the insurance program, which is administered by the U.S. Dept. of Homeland Security's Federal Emergency Management Agency. Her latest hope is a submission by the Buoyant Foundation Project (BFP), a non-profit she founded and directs, to the U.S. Dept. of Housing and Urban Development's "Rebuild by Design" competition. At ENR press time on Aug. 5, English was on tenterhooks, waiting for HUD's Aug. 9 announcement of the competition's 10 finalists.
"I haven't given up. I think there is an air of change," she says.
Meanwhile, English and her BFP team have expanded their sights and sites to Latin America. Later this year or early next year, work is expected to begin on a prototype for a 10-house pilot project in Tipitapa, Nicaragua, funded by the government.
The simple, affordable houses, which will allow the indigenous population to continue life near the water rather than relocating against their will to higher ground, will be built from kits of bamboo (see rendering, p. 32). "The challenge is coming to market with a solution that is affordable," says Ben Sandzer-Bell, a BFP team member and chief resilience officer for Climate Adaptation Systems. The Tipitapa house is expected to cost about $20,000.
In 2007, the BFP tested a prototype for amphibious retrofits of shotgun-style houses in New Orleans (see drawing, p. 32). The system would come as a kit of small-enough parts that most of it would be able to be installed by two people without heavy equipment—for about $10,000. Full installation by a contractor would cost about $20,000 for a maximum 1,000-sq-ft shotgun house. "We can say it would cost $20 to $25 per square foot or probably less over time with more experience," says English.
The largest installation of amphibious houses is in the Netherlands at a project called Maasbommel, built in 2007 (see photo, p. 33). In a 2012 flood, the 16 houses performed very well, with no damage, says Chris Zevenbergen, managing director for business development at Maasbommel's builder, Dura Vermeer Group NV. There are plans for more than 40 more houses in two other projects, he says.
Maasbommel foundations consist of a small concrete bowl within a bigger, fixed bowl. When the bigger bowl fills with water, the smaller bowl floats. Vertical posts guide it. "The buoyant systems are fabricated elsewhere and transported to the site," says Zevenbergen.
Amphibious buildings are starting to catch on. Work has begun on the U.K.'s first amphibious house, designed by Baca Architects. Completion is expected next year. The house is located on an island in the Thames in Marlow, Buckinghamshire.
There are no amphibious high-rises. That will change, if English has her way. In her scheme, fixed upper levels would bear on two-story-tall freestanding columns above amphibious levels, possibly topped by a green roof. The scheme is ideal for low-lying cities because it doesn't destroy the streetscape, says English.