Amphibious house | Baca Architects

The UK’s first amphibious house, built on the banks of the River Thames in Marlow, will be habitable for its new owners next month; just in time for the predicted harsh winter weather.

An amphibious house is a building that rests on the ground on fixed foundations but, whenever a flood occurs, rises up in its dock and floats there buoyed by the floodwater.
 
Using the latest technology, the property is a major breakthrough for British architects and engineers who have been searching for many years for a solution to mitigate the risk - and damage - of water ingress to homes in flood-prone areas.

The truly unique 225sqm house – located just 10m from the river’s edge - replaces a dilapidated bungalow with a contemporary family home that has been carefully designed to respond to the uncertainties of future climate change.

Designed by Baca Architects, specialists in waterfront architecture and flood-resilient aquatecture, the house is located on a small island in the picturesque stretch of the Thames that passes through Marlow, in Buckinghamshire, a site designated as Flood Zone 3b and a Conservation Area.

While the house will be a modern, highly insulated, low energy building, including large high-performance windows, the architects have ensured that it is also sympathetic to the locality; a scenic spot with very strict planning guidelines. The property has pitched roofs and a chimney to complement the irregular roofline of neighbouring homes and an overall footprint that is no larger than the old demolished property.

The new house has been designed to cope with up to 2.5m of floodwater, well above the predicted flood levels and future projected flood levels for the area.

A carefully laid out garden acts as a natural early warning flood system, with terraces set at different levels designed to flood incrementally to alert the occupants well before the water reaches a threatening level, a system that the architects refer to as an ‘intuitive landscape’. The lowest terrace is planted with reeds, the next with shrubs and plants, then a lawn and the highest step is a patio with direct access into the open-plan living space. Following flooding the demarcated levels also help to manage run-off from the house as flood waters begin to subside as well as reducing siltation of the dock.

The clever house is a lightweight timber construction which rests on a concrete hull, creating a free-floating pontoon, while the whole house is set between four ‘dolphins’, permanent vertical guideposts that keep it in place. These guideposts, more often found in marinas, have been integrated with the design and are a striking visible feature on the exterior of the building.

The modern home also includes water saving and energy saving devices to create a super environmentally friendly building which, combined with its amphibious capability, enables its occupants to adapt to future climate changes.

Richard Coutts, director of Baca Architects, said; “The planning process obviously took a bit more time than an ordinary planning application and involved our team in extensive consultations and co-operations with the local authority. From the outset of the design process we sought expert advice from the Environment Agency to determine the most appropriate construction model to mitigate the flood risk on this particular section of the river and that would also provide a safe dwelling, sympathetic to its setting and fit for the challenges of the 21st Century.”

Building an amphibious home currently costs around 20% to 25% more than a similar sized house; with construction costs predicted to fall as builders and manufacturers get to grips with the much wetter weather phenomenon and embrace new thinking and technology. Coutts adds: “It’s a relatively small uplift in price that many flood victims will probably view as small change for the peace of mind it affords; as well as being a practical solution for anyone considering building a new home by water in the future”.