---
title: "This house only floats when the river forces it to"
locale: "en"
url: "https://irz.fr/en/articles/amphibious-house-rises-with-water-en"
markdown_url: "https://irz.fr/en/articles/amphibious-house-rises-with-water-en.md"
category: "ideas"
tags: ["architecture", "flooding", "construction", "climate adaptation", "amphibious house"]
published_at: "2026-08-20T08:18:00.000Z"
author: "Hugo Marchal"
translation: "https://irz.fr/fr/articles/amphibious-house-rises-with-water-fr.md"
---

# This house only floats when the river forces it to

An amphibious house sits on the ground most of the time, then rises with a flood. Making it buoyant is not the hardest part: guides, utilities and access all have to tolerate metres of vertical movement.

Designboom recently brought amphibious housing back into view, and the photographs make the idea look almost self-explanatory: colourful houses beside water, ready to float when the river rises.[1](https://www.designboom.com/architecture/water-rises-amphibious-homes-float/) What those photographs hide is the awkward part of the arrangement, because on an ordinary dry day these buildings are supposed to behave like houses on land.

Maasbommel, on the Meuse in the Netherlands, has 32 amphibious houses completed in 2005 alongside 14 permanently floating homes. The amphibious ones rest on their bases until floodwater provides enough lift; then the whole building rises between vertical guides and later settles back into place as the river falls.[4](https://climate-adapt.eea.europa.eu/en/metadata/case-studies/amphibious-housing-in-maasbommel-the-netherlands)

It sounds simple until you imagine everything attached to a house. Walls can move with the floor, while the sewer connection, electricity network, road and neighbour’s garden remain where they were. Once those fixed surroundings are included in the picture, designing the buoyant base starts to look like the beginning of the problem rather than its solution.

## Dry most days

The Dutch houses use a light upper structure over a hollow concrete base. Under normal conditions the base sits in a dock and carries the building in the familiar way; during a flood, displaced water begins to support it, while large guidance posts keep the structure from wandering sideways.[5](https://www.buoyantfoundation.org/resources/maasbommel)

For Maasbommel the permitted travel was substantial, **up to 5.5 metres vertically**,[4](https://climate-adapt.eea.europa.eu/en/metadata/case-studies/amphibious-housing-in-maasbommel-the-netherlands) which is enough to turn an innocent-looking rigid connection into a very effective way of breaking something. Pipes and cables therefore need room to move, while an access route that works at ground level may end several metres below the front door once the house has risen.

> One house, four states
> **The structure changes jobs during a flood**
> - Resting: the base sits in its dock.: 1
> - Lifting: rising water gradually provides buoyancy.: 2
> - Guided: posts constrain horizontal movement.: 3
> - Settling: the house descends and rests again after the flood.: 4
> IRZ synthesis from Climate-ADAPT and the Buoyant Foundation Project.

There is a useful inversion here: descriptions of resilient buildings usually list whatever has been made stronger or more watertight, whereas part of the resilience in Maasbommel comes from deciding in advance which movement is acceptable and giving that movement a controlled path.

## The loose ends

Services are where the concept stops being a diagram and becomes engineering, since water, sewage, electricity and sometimes gas all arrive from fixed infrastructure while the building above them has permission to move.

The Maasbommel connections were designed around that travel, and BACA Architects faced the same issue with an amphibious house on an island in the Thames, where flexible service pipes have roughly three metres of extension available.[2](https://www.baca.uk.com/projects/amphibious-house) BACA calls the arrangement “elephant-cabling”, a memorable name for a very physical requirement: connections must bend and lengthen as the building rises while remaining usable.

> Illustration: BACA Architects amphibious house on an island in the River Thames. In dry conditions the building reads like an ordinary house. Its dock, guides and flexible services are sized for the much rarer moment when the structure has to rise. Credit: [BACA Architects](https://www.baca.uk.com/projects/amphibious-house).

The British project also shows why anybody would bother, because planning constraints made a conventionally raised house unattractive: pushing the floor high enough for the predicted flood level would have separated the new building from its garden and increased its visible height. BACA’s 225 m² house can remain comparatively low during daily life and gain height only when floodwater arrives.[2](https://www.baca.uk.com/projects/amphibious-house)

The trade is peculiar but clear: the design spends money on a moving foundation in exchange for keeping the house close to its garden during all the ordinary days when the river stays put.

## The front door

A house can survive perfectly and still fail its occupants, which is why Climate-ADAPT notes that Maasbommel required an escape route usable while the houses were afloat; the ordinary bridge to the dwelling could not be treated as sufficient on its own.[4](https://climate-adapt.eea.europa.eu/en/metadata/case-studies/amphibious-housing-in-maasbommel-the-netherlands)

BACA’s Thames project operates under a different emergency policy: residents are expected to leave the island when the Environment Agency issues a major flood warning, even though the house itself is designed to ride out the water.[3](https://www.baca.uk.com/research/case-study-amphibious-house) Glossy coverage can easily blur those two claims, but keeping the building intact during a flood and keeping daily life running inside it are plainly different jobs.

This also explains why copying the concrete hull and guideposts would be a poor shortcut, since the complete system includes the route out, the warning procedure, the utilities and the assumptions about whether people remain in place.

## 2011 arrived

Maasbommel had an advantage that many experimental buildings never get: the river eventually ran the test, and in January 2011, six years after completion, the water rose far enough to lift the amphibious houses.[6](https://climate-adapt.eea.europa.eu/en/metadata/case-studies/amphibious-housing-in-maasbommel-the-netherlands/11310092.pdf/@@download/file/11310092.pdf) Climate-ADAPT and the Buoyant Foundation Project report that the homes floated as intended and settled back with no problems identified during the floating or return phases.[4](https://climate-adapt.eea.europa.eu/en/metadata/case-studies/amphibious-housing-in-maasbommel-the-netherlands)[5](https://www.buoyantfoundation.org/resources/maasbommel)

The event cannot tell us how the same design would behave on a fast river, on a coast exposed to waves, or under debris loads for which it was never sized, although it does establish something more modest and more useful: the guides, connections, buoyant bases and landing arrangement went through a real flood cycle after years of ordinary use.

A flotation test in a controlled basin tells you whether Archimedes still works; a flood years later tells you whether the collection of guides, pipes, cables, access arrangements and ordinary construction around that buoyant base has managed to keep up with him.

## Paper barriers

The Dutch example has been around for two decades and amphibious housing has not spread across every floodplain; Climate-ADAPT estimated only several hundred Dutch “water houses” in 2020 and points to higher construction costs, a limited buyer market and difficulty obtaining permits in places already labelled risky.[4](https://climate-adapt.eea.europa.eu/en/metadata/case-studies/amphibious-housing-in-maasbommel-the-netherlands)

Even naming the building became consequential, because an amphibious property could fall under rules for ordinary housing, floating dwellings or holiday accommodation, each with different consequences for occupancy and planning. The Buoyant Foundation Project describes this legal uncertainty as a recurring obstacle around Maasbommel.[5](https://www.buoyantfoundation.org/resources/maasbommel)

Cost matters too, and BACA says its British amphibious house came in at roughly **20% more** than an equivalent conventional house with a basement.[3](https://www.baca.uk.com/research/case-study-amphibious-house) One bespoke project is a poor price index, although the direction is unsurprising because a foundation that can lift, remain guided, keep its services attached and land correctly asks for work that a fixed slab never needs.

## Permission to move

The part worth borrowing from amphibious housing is less romantic than “a house that floats”. Here, movement has a designed route, a limit and supporting interfaces instead of being treated as an accident.

We already use the same logic elsewhere without much drama, from the expansion joints of bridges to vibration mounts under machines and service loops in cables whose endpoints move relative to one another. Amphibious architecture simply pushes controlled movement to the scale of an entire home, where the consequences become unusually visible.

For years, a Maasbommel house can remain exactly where a house is expected to be. A rising river temporarily turns its foundation into something closer to a hull. Concrete floating is the easy headline; the cleverer work sits in the rest of the building, which has been arranged around the possibility that this heavy base may one day leave the ground.

## References

1. [Designboom, Water rises, amphibious homes float](https://www.designboom.com/architecture/water-rises-amphibious-homes-float/)
2. [BACA Architects, Amphibious House](https://www.baca.uk.com/projects/amphibious-house)
3. [BACA Architects, Case Study Amphibious House](https://www.baca.uk.com/research/case-study-amphibious-house)
4. [Climate-ADAPT, Amphibious housing in Maasbommel, the Netherlands](https://climate-adapt.eea.europa.eu/en/metadata/case-studies/amphibious-housing-in-maasbommel-the-netherlands)
5. [Buoyant Foundation Project, Maasbommel](https://www.buoyantfoundation.org/resources/maasbommel)
6. [Climate-ADAPT, Project review: Floating Homes De Gouden Kust](https://climate-adapt.eea.europa.eu/en/metadata/case-studies/amphibious-housing-in-maasbommel-the-netherlands/11310092.pdf/@@download/file/11310092.pdf)