WHAT IS AMPHIBIOUS ARCHITECTURE?
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 are the bases for resilient communities.
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 guideposts 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. The posts that provide vertical guidance 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 guideposts 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)
- The house is elevated to whatever level is required for it to stay above water
- Unlike permanent static elevation, the house is still protected even in an extreme flood
- Installation is usually much less expensive than for permanent static elevation
- The house remains low to the ground, so there are no long flights of stairs to climb
- The entire structure is less susceptible to hurricane wind damage
- Long-term issues of soil subsidence and rising sea level are already accommodated
- The retrofitted house looks essentially the same as it did before
- Its original (traditional or historic) architecture is preserved
- The neighborhood retains its original character
Link To: "Flood Performance of Amphibious Housing" (PDF of Powerpoint)
BFP MISSION STATEMENT
The 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 historic housing. Retrofitting the city's traditional elevated wooden shotgun houses with buoyant (amphibious) foundations could prevent not only devastating flood damage, but also the destruction of neighborhood character that results from permanent static elevation high above the ground. Buoyant foundations can provide increased safety and resilience in cases of extreme flooding, as well as support the recovery of both physical and social structures. The mission of the BFP and its amphibious retrofit strategy have, since 2006, broadened to apply not only to post-Katrina New Orleans but also to numerous other flood-sensitive 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)
Watch a webinar on amphibious architecture and the work of the Buoyant Foundation Project presented by Dr. Elizabeth English of the University of Waterloo School of Architecture.
Originally delivered as part Rising Waters Flood Solutions Virtual Seminar.