Story at a glance

  • Whether amphibious or over water, floating houses have the potential to resist sea-level rise.
  • Floating houses cost 8-16 percent more than land-based structures.
  • Floating houses can help revitalize neglected waterfronts.

In Helsinki, Finland, people are already clamoring for the houses. More than 40 of them will be built offsite, then floated into the harbor. That’s where they will stay, anchored to the seabed, rising and falling with the water levels.

“If you have a city area where you don’t have any land area, but you have a lot of water, you can create more building areas with floating infrastructure. You can expand the land on water,” says Tytti Sirola, founder of Bluet, one of the companies spearheading the work on the floating development.

With climate change continuing apace, the advantages of a floating house are obvious, particularly for an archipelago city like Helsinki. “We have a lot of areas, especially island areas, on the waterfront – sea water is rising, but it doesn’t affect these houses,” adds Sirola.

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The homes are part of a supermodern development in the Scandinavian city, called Kalasatama, and installation is expected to begin in 2022. Though innovative, these dwellings are not the first example of floating architecture, nor are they likely to be the last.

Once a pipe dream, the idea that humans could start constructing and living in houses designed to work with the water is becoming more realistic, if not exactly mainstream. As well as these innovative forays into the world of floating houses, some jurisdictions, including British Columbia in Canada and Portland, Ore., have developed standards that could underpin floating home construction more broadly.

Floating houses can be designed to sit permanently on a body of water, or as “amphibious” structures that rise when an area floods. There have already been some successful prototypes, particularly in the Netherlands, where around a third of the land is below sea level.

The idea of living in floating accommodation isn’t new. To this day, the indigenous Uros people of Peru and Bolivia live on manmade islands constructed from reeds on Lake Titicaca. It is an ancient practice originally conceived as a defense mechanism against unwelcoming locals. Climate change is a very different challenge, but floating houses again offer a potential defence. Houses built on stilts are already a common sight across many countries in the global south – communities in Bangladesh have even developed floating farms – but the western world has typically been slower to adapt to life on the water, and floating homes remain an alien concept.

“People think it’s a bit risky, a bit dangerous, which it probably isn’t, and they prefer to be with their feet on dry land. They’re not particularly adventurous,” says Edmund Penning-Rowsell, a professor at the Flood Hazard Research Center at Middlesex University in London, and the author of a recent paper analyzing the potential for the development of floating houses. “Property is a source of savings, and they’d rather have it as conventional as possible.”

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In a world where cities are becoming increasingly crowded, and urban land increasingly scarce, building floating houses in floodplains can offer an opportunity to build up real estate value in areas once considered no-go zones, while also maintaining the land’s role as a sponge that protects the wider area against flooding.

“We shouldn’t sterilize our floodplains and think they’re not good for anything except sheep or cows. No, we can actually develop them sensibly, either with protection by defence or protection by floating or amphibious housing,” adds Penning-Rowsell.

Of course, there are many problems with floating houses. Could you still get an ambulance in the case of a heart attack? Is your toddler at risk of drowning? Will you be able to sell it? These mental barriers to living on water are not easy to overcome, and, alongside technical and regulatory barriers, help to explain why the concept has yet to hit the mainstream.

On the other hand, they are often cool. The amphibious house, designed by Baca Architects in London, is a gleaming box of glass in a stretch of the River Thames, which rises and falls with the water level. It’s a luxury solution in a nation that seems determined to build on its risky floodplains.

While the market for floating properties is still uncertain, there are certain groups to which these developments will appeal, according to the study. These include people who like to feel close to nature or embedded within a community, people who live an active outdoors lifestyle, and young high earners who want to make a statement with a unique house in the city.

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While the floodplain land used to build these developments is often cheap, the houses themselves tend to be expensive: a 2004 study in the Netherlands revealed that floating homes are around 8-16 percent more expensive than their landlubbing counterparts.

Climate change is expected to have the worst impacts on communities that are already poor and marginalized, and pricy architectural experiments are probably not going to emerge as the most equitable solution. Indeed, floating cities have been proposed by Paypal founder and conservative libertarian Peter Thiel as a means to escape government regulation and taxes, while also posing as a solution to rising sea levels.

Nonetheless, their social benefit extends beyond allowing wealthy people to buy their way out of the climate crisis. Floating developments are well suited to the post-industrial landscapes that dominate the waterfronts of many of the world’s cities, helping to revitalize these urban landscapes and creating new communities in once neglected areas.

It could also relieve some pressure on the National Flood Insurance Program, the insurance scheme run by Federal Emergency Management Agency (FEMA) that is a lifeline to the millions of Americans who live in flood-prone areas. But the scheme cannot keep up with the losses: NFIP currently owes more than $20 billion to the U.S. Treasury.

“In the States, houses get smashed every year and some houses get smashed all the time. That’s why NFIP is bankrupt, really. If you had a floating house development, you minimise damage,” says Penning-Rowsell. “This could actually cut down insurance claims and help the National Flood Insurance Program get back into some kind of solvency.”

Published on Mar 06, 2020