Along the banks of the River Thames sits a house that—beyond its timber-clad façade and pitched roof—is unique from its small scattering of neighbors in Marlow, Buckinghamshire.
Baca Architects’s Formosa is an amphibious house. Though its structure rests upon grounded, fixed foundations, it is designed to rise up in its dock and float on floodwater before gently settling back down once the water lowers to its normal level. A handful of similar projects have also been built in Holland and New Orleans, but Formosa, which finished testing and reached completion this month, is the first of its kind in the U.K.
The 2,400-square-foot home is located just over 30 feet from where a picturesque stretch of the Thames crosses the island to form a designated Flood Zone 3B and conservation area. Longtime advocates of waterfront and flood resilient architecture, the firm’s founders, Richard Coutts and Robert Barker, designed the Archimedes principle-inspired home to withstand up to 2.5 meters, or approximately eight feet, of floodwater—well above the area’s average, predicted flood levels.
As the dock fills from the ground and the building rises, flexible, extendable pipes rise up to three meters (10 feet) and keep the house buoyant, fully operational, and accessible during any flood event. Like anything with moving parts, the house requires occasional maintenance, and will be tested every five years to insure all its mechanisms are in good, working order.
“People have always enjoyed living by water. Our senses are stimulated by the wind and soothing sounds of the flow of water and its associated wildlife, or the play of light reflected on the river. These aesthetic, environmental and recreational benefits attract a premium for dwellings in waterside locations and, despite the price premium, these properties are often vulnerable to flooding,” Coutts said.
Amphibious houses such as Formosa are a breakthrough in residential design; architects and engineers have long been seeking a solution to mitigate the high risk of damages in flood-prone areas.
In addition to its flood-resistant technology, the house is also energy efficient and features a cozy, modern aesthetic. Its large, high-performance windows that look out onto the Thames are tightly insulated. A pitched roofline complements and satisfies the scenic neighborhood’s strict planning guidelines, and a thoughtfully sited and sloped garden doubles as natural, early warning system.
According to the architects, the cost of building an amphibious home is just slightly higher (20% more) than building a similar, standard home. The firm expects that percentage to dip as builders and manufacturers become more savvy on wet-weather building technology.
“Ideally the whole riverside community should be designed to take flooding into account, rather than just the odd house, so the consequences can be mitigated for all. Amphibious design is one of a host of new solutions that will enable residents to live safely by water and adapt to the challenges of climate change.”