Amphibious architecture refers to an alternative flood mitigation strategy that allows an otherwise-ordinary structure to float on the surface of rising floodwater rather than succumb to inundation. An amphibious foundation retains a home's connection to the ground by resting firmly on the earth under usual circumstances, yet it allows a house to float as high as necessary when flooding occurs. A buoyancy system beneath the house displaces water to provide flotation as needed, and a vertical guidance system allows the rising and falling house to return to exactly the same place upon descent. Amphibious construction is a flood mitigation strategy that works in synchrony with a floodprone region's natural cycles of flooding, rather than attempting to obstruct them. Amphibious foundations make homes resilient; resilient homes foster resilient communities.
What is Amphibious Architecture?
Link To: "Amphibious Foundations and the Buoyant Foundation Project: Innovative Strategies For Flood-Resilient Housing" (Conference paper, Paris, 2009)
What Is a Buoyant Foundation?A buoyant foundation is a particular type of amphibious foundation that is specifically designed to be retrofitted to an existing house that is already slightly elevated off the ground and supported on short piers. The system consists of three basic elements: buoyancy blocks underneath the house that provide flotation, vertical guidance posts that prevent the house from going anywhere except straight up and down, and a structural sub-frame that ties everything together. It basically works like a floating dock. A steel frame that holds the flotation blocks is attached to the underside of the house. Four vertical guidance posts are installed not far from the corners of the house. Utility lines have either self-sealing 'breakaway' connections or long, coiled 'umbilical' lines. When flooding occurs, the flotation blocks lift the house and the vertical guidance posts resist any lateral forces from wind and/or flowing water. Any house that can be elevated can be made amphibious.
Link To: "The Buoyant Foundation Project" (Video animation of assembly)
Advantages of Buoyant Foundations
- Elevates house to whatever level is required to stay above water
- Unlike permanent static elevation, house is still protected even in an extreme flood
- Usually much less expensive than permanent static elevation
- House remains low to the ground, so there are no long flights of stairs
- Structure is less susceptible to hurricane wind damage
- Accommodates long-term issues of soil subsidence and rising sea level
- Retrofitted house looks essentially the same as before
- Original traditional architecture is preserved
- Neighborhood retains original character
Link To: "Flood Performance of Amphibious Housing" (PDF)
BFP Mission StatementThe mission of the Buoyant Foundation Project (BFP), when originally founded in 2006, was to support the recovery of New Orleans' unique and endangered traditional cultures by providing a strategy for the safe and sustainable restoration of traditional housing. Flood-proofing the city's traditional elevated wooden shotgun houses by retrofitting them with buoyant (amphibious) foundations could avoid the destruction of neighborhood character that results from permanent static elevation high off the ground. Buoyant foundations provide increased safety and resilience in cases of extreme flooding and support restoration of both physical and social structures of not only pre-Katrina New Orleans neighborhoods, but other flood prone locations around the world. The Buoyant Foundation Project is a registered non-profit organization in the State of Louisiana.
Link To: "The Buoyant Foundation Project Movie" (Video)
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