The wave of floods that hit Britain in April focused attention, once again, on the vulnerability of homes in low-lying areas. Against a background of news images of householders baling out their homes, there were renewed calls to ban all building of new houses in flood-prone districts.
But what if a house could simply rise and fall with the waters? That’s the vision of Baca Architects, designers of the UK’s first ‘amphibious house’, which has just received planning permission for a site near Marlow, in Buckinghamshire, on the banks of the Thames.
The lightweight, timber-framed structure sits on a floating concrete base that is built within a fixed ‘wet dock’ foundation. In the event of a flood, the concrete base rises up as the dock fills with water, ensuring the house floats safely above the waves. The base effectively acts as a free-floating pontoon, and should have a lifetime of around 100 years before needing renewal or replacement.
Amphibious houses have already made an appearance in the Netherlands, where they’ve proven themselves under fire, or rather, above water. Dutch company Deltasync has even used their success as a template for ambitious designs for floating cities [see 'Floating cities a vision of the future']. The Baca house is based on the same principles as those of the Dutch, and will be the largest amphibious home to date, with building expected to commence later this year.
At an estimated £1.5 million, this (sizeable, prestige-style) house is 20-25% more expensive to build than its conventional equivalent. But this could be just the start, as Baca Architects have more amphibious designs up their sleeve. Working with the Climate Adaptive Neighbourhoods [CAN] Project, they’ve been tasked to develop strategies for building flood-resilient homes on a floodplain in Norwich.
‘Climate proofing’ urban areas is a growing area of focus for architects and planners. Amphibious architecture looks set to join rain gardens, green roofs and permeable paving in the array of techniques available. Will McBain, who specialises in flood risk management at Arup, believes it has “a definite place within the broad spectrum of measures that can be taken to increase community flood resilience”. But he adds that the flood hazard in the UK is different to that in the Netherlands. “Rivers are smaller and ‘flashier’ in their response to rainfall, and water level ranges are frequently larger.” So, careful risk assessment is essential.