UK's "first amphibious house" can float
on floodwater like a boat in a dock


Work is nearing completion on the Amphibious House by Baca Architects – a family home on an island in the middle of the River Thames that can float on rising floodwater like a ship in its dock.

Formosa The Amphibious House by Baca
The Amphibious House nears completion

The house by London studio Baca Architects was designed for a couple who had been looking for a site to build a home on the flood-prone river island near Marlow in Buckinghamshire for seven years.

"During the flood event the whole house will raise gently like a boat and will keep all of the habitable spaces safe above the flood level," Baca co-founder Richard Coutts told Dezeen.

The couple chose Baca on the strength of research work on waterways that the firm has been carrying out with the UK's Department for Environment, Food & Rural Affairs called The LifE (Long-term Initiatives for Flood-risk Environments) Project.

Formosa The Amphibious House by Baca
The original design for the Amphibious House

"Rather than building flood defences, [The LifE Project] considers a different approach, to acknowledge man cannot beat nature and to actually make space for water," said Coutts. "Our work, until recently, was better known in Holland than here in the UK."

Baca considered a number of different approaches to dealing with the unpredictable water levels on the site, including a fully floating structure  – an option ruled out by officials from the government's Environment Agency – and raising the house on stilts.

"If we'd have gone for an elevated house the ground floor would have been so high, almost two metres off the ground, the house would have looked out of keeping with its neighbours," explained Coutts. "The benefit of an 'amphibious house' is that it looks in all intents and purposes like a normal house. Rather than having a house that's up in the air you get proper engagement with the garden."

Formosa The Amphibious House by Baca
The garden design incorporates terraces that act as an "early warning system" for flooding

The lightweight timber-framed structure is fairly traditional in its form, but sits inside an excavated "wet dock" made from steel sheet piling with a mesh base to allow water to enter and escape naturally. Clad in zinc shingles with glazed gables, this structure is independent of the house, which has a foundation of waterproofed concrete that wraps around the lower ground floor, acting like the hull of a ship.

The design was developed according to the Archimedes principle: "the house's mass and volume are less than the equivalent of water, and that's what creates buoyancy," explained Coutts.

Four posts, nicknamed "dolphins" by the project's engineer, act as vertical guideposts to allow it to slide up and down when it needs to move. These could be extended in future to cope with rising water levels.

Formosa The Amphibious House by Baca
Diagram – click for larger image

"In the same way you have Liverpool Docks or the Royal Docks, which were man-made enclosures for building ships, this is a lot smaller scale and in this circumstance its built inland and will contain the house," said Coutts. "When a flood event occurs, the river will rise gently and within the base of the wet dock the water will then start to rise."

On the riverside, the garden is terraced to act as an "early warning system" for rising waters – when the first two terraces fill with water the house should begin to rise.

Formosa The Amphibious House by Baca
Diagram – click for larger image

"At the front of our site we've designed something which is called an intuitive landscape. It's a visual early warning system to the client to say 'look your first two terraces are inundated with water' and it's an intuitive way to say change is happening within the river, the first two flood cells are filled, your house should have started moving."

The house is currently designed to travel up to two and a half metres, based on worst-case scenario flood predications from the Environmental Agency and some additional tolerance for climate change.

Services are connected through "elephant cabling" – a flexible cable that carries electricity water and sewage. For safety reasons, the house only uses electric power and no gas.

Formosa The Amphibious House by Baca
The "wet dock" under construction

The island has no road access, so the architects used reclaimed NATO military equipment to build a floating pontoon that was used as a "chain ferry" to carry materials to the site. The size of the pieces of steel and glazing used in the construction of the house also had to be restricted due to the lack of mechanical lifting equipment.

"Prior to this project there had never been an amphibious house that had secured planning in England," said Coutts. "It wasn't covered by building regulations and is also located in a conservation area so during the course of the project we have had to go through numerous negotiations with all the various statutory bodies to set a responsible president for other houses that may well follow."

Planning restrictions meant the house had to recreate the footprint of the previous structure that occupied the site, so the architects designed the structure with a habitable basement level to accommodate extra living space and a cinema room.

Formosa The Amphibious House by Baca
The incomplete interior during the filming of the TV programme Grand Designs

The structure is accessed via a flight of six steps that lead up to the raised ground floor, which contains an open-plan living and dining room as well as two bedrooms.

A mezzanine floor contains the master bedroom, with an en-suite bathroom and steam room.

A flood on site delayed construction, which was due to finish in time for the broadcast of the project on UK home building TV show Grand Designs tonight but will now complete next month.

Project Credits: 

Project Architect: Richard Coutts
Design Team: Baca Architects: Robert Barker, Riccardo Pellizzon, Robert Pattison
Structural Engineer: Techniker
Hydrological Engineer: HR Wallingfords

  • sean

    I guess we are going to see this on Grand Designs.

    • Kevin McCloud

      Slow clap.

      • sean

        Ah, the comment is not as funny since they added the last pic :) Nice to hear from you all the same. Love your show, cheers. S

  • Flood victim

    And the LORD said to Noah, “Go into the ark and watch neighbours suffer.”

    Love the idea but it needs to be cheaper. It a fantastic solution to our recent troubles in the UK.

  • JDM

    Nice, but how you solve the problem of supply connections from water, electricity and gas?

    Where is the front door? How do you get in and out? Do you get in depending on the level of water?

    • JC

      It says in the article RE supplies.

      Not sure about the front door situation. I’m sure they wouldn’t have overlooked that though!?

      My question would be about the build-up of silt under the house post flooding… again I’m sure they wouldn’t have overlooked it, just curious as to the solution.

      • Ralph Kent

        I’m interested in the answer to the silt question too. I’m guessing they have to artificially float the house and periodically ‘vacuum’ the trough out using some sort of system like a pool filtration system on a hose? But I would be interested to know what the actual solution is, and how frequently they need to do this.

    • James Burt

      I watched the GD episode and was very surprised they didn’t cover the services connections issue. I’m also none the wiser about how they cast the concrete basement slab within the dry dock.

  • Concerned Citizen

    No plans, no building elevations? What?

  • Marisa Rodriguez

    Cheaper and more practical to build on stilts.

    • janine

      This is also discussed in the article.

    • brian whittle

      They would have been limited to one floor and what could be fitted in the roof due to planning restrictions, this has two floors and a mezzanine.

  • Jimmy Breeze

    Not funny at all was it… Twitter really shows some people up!

  • M Luce

    What stops the silt settling in the space below the house in flood?

  • Marisa Rodriguez

    Given enough financial means, there is no such thing as an unbuildable or impractical site for a home.

  • JP

    In essence it’s a zinc clad, glazed timber and ply shed sat on a concrete ‘Mulberry harbour’, sitting in a dry/wet dock (a swimming pool)? As for the architect’s claim that this is the first floating house in the UK… Not a moored-up houseboat then?

  • Luis César

    Hi, just to say this is really a good idea and to all the staff and owner, you did a very good job. Congratulations. Cheers, Luis.