This article originally appeared on Yale Environment 360.
When a severe storm hit in October, residents of the floating community of Schoonschip in Amsterdam had no doubts they could pull through. They tied up their bikes and outdoor benches, checked with neighbors to make sure everyone had enough food and water, and hunkered down as their neighborhood slid up and down on its fundamental steel pillars. , rising with the water and sinking back to its original position after the rain subsided.
“We feel safer in a storm because we are floating,” said Siti Boelen, a Dutch television producer who moved to Schoonschip two years ago. “I think it’s a bit odd that building on water isn’t a global priority.”
As sea levels rise and supercharged storms cause waters to swell, floating neighborhoods offer a flood defense experience that could make coastal communities more resilient to climate change. In the Netherlands, where land is scarce but densely populated, the demand for such houses is increasing. And, as more people seek to build on the water there, authorities are scrambling to update zoning laws to make it easier to build floating homes.
“The municipality wants to expand the floating concept because it is a multifunctional use of space for housing, and because the sustainable way is the way forward,” said Nienke van Renssen, a councilor Amsterdam municipal member of the GreenLeft party.
The floating communities in the Netherlands that have emerged over the past decade have served as proof of concept for larger-scale projects led by Dutch engineers, not only in European countries such as Britain, France and Norway, but also in places as far apart as French Polynesia and the Maldives, the Indian Ocean nation facing an existential threat from rising sea levels. There’s even a proposal for islands floating in the Baltic sea upon which small towns would be built.
Instead of seeing water as an enemy, we see it as an opportunity.
A floating home can be built on any shoreline and is able to cope with rising seas or rain-induced flooding by floating on the surface of the water. Unlike houseboats, which can easily be unmoored and moved, floating homes are fixed to the shore, often resting on steel poles, and are usually connected to the local sewage system and electricity grid. They are structurally similar to houses built on land, but instead of a basement, they have a concrete shell that acts as a counterweight, allowing them to remain stable in water. In the Netherlands, these are often three-storey, square-shaped prefabricated townhouses built off-site with conventional materials such as wood, steel and glass. For cities facing worsening flooding and a shortage of building land, floating homes are a potential model for expanding urban housing in the age of climate change.
Koen Olthuis, who founded in 2003 Aqua studio, a Dutch architectural firm focused exclusively on floating buildings, said the relatively low-tech nature of floating homes is potentially their biggest advantage. The homes he designs are stabilized by posts dug approximately 213 feet into the ground and fitted with shock-absorbing materials to reduce the feeling of nearby wave movement. The houses go up when the waters rise and go down when the waters recede. But despite their apparent simplicity, Olthuis argues they have the potential to transform cities in ways not seen since the introduction of the elevator, which pushed skylines upwards.
“We now have the technology, the ability to build on water,” said Olthuis, who has designed 300 floating homes, offices, schools and health centers. He added that he and his colleagues “don’t see themselves as architects, but as city doctors, and we see water as medicine”.
A cross section of a houseboat. (Source: Ahlqvist and Almqvist)
In the Netherlands, a country built largely on reclaimed land and a third of which remains below sea level, the idea is not so far-fetched. In Amsterdam, which has nearly 3,000 officially registered traditional houseboats on its canals, hundreds of people have moved into houseboats in previously neglected neighborhoods.
Schoonschip, designed by the Dutch firm Space&Matter, consists of 30 houses, half of which are duplex, on the edge of a canal in a former industrial area. The neighborhood is a short ferry ride from central Amsterdam, where many residents work. Community members share almost everything, including bicycles, cars, and food purchased from local farmers. Each building runs its own heat pump and devotes about a third of its roof to greenery and solar panels. Residents sell excess electricity to each other and to the national grid.
“Living on the water is normal for us, which is exactly the point,” said Marjan de Blok, a Dutch television producer who started the project in 2009 by organizing the collective of architects, legal experts, of engineers and residents who worked to obtain the project. of the ground.
Rotterdam, located 90% below sea level and the site of Europe’s largest port, is home to the largest tallest floating office building, as well as a floating farm where cows are milked by robots, supplying dairy products to local grocery stores. Since the launch in 2010 of the floating pavilion, a solar-powered meeting and event space in the Port of Rotterdam, the city has stepped up its efforts to incorporate such projects, naming floating buildings a pillar of its Climate-proof and adaptive strategy.
“Over the past 15 years, we have reinvented ourselves as a city in the delta,” said Arnoud Molenaar, head of resilience in Rotterdam. “Instead of seeing water as an enemy, we see it as an opportunity.”
A Dutch company is working on a series of floating islands in the Baltic Sea with accommodation for 50,000 people.
To help protect cities from climate change, the Dutch government launched its “Room for the River” program in 2006, which strategically allows certain areas to be flooded during periods of heavy rain, a paradigm shift that seeks adopt rather than resist the rising waters. levels. Olthuis says the housing shortage in the Netherlands could fuel demand for floating homes, including in “Room for the River” areas where flooding will, at least for part of the year, be part of the landscape. Experts say that to relieve the housing shortage in the Netherlands, 1 million new homes will need to be built over the next 10 years. Floating homes could help fill the gap shortage land suitable for development.
Dutch companies specializing in floating constructions have been inundated with requests from foreign developers to undertake more ambitious projects. Blue21, a Dutch technology company focused on floating buildings, is working on a proposed series of floating islands in the Baltic Sea that would house 50,000 people and connect to a privately funded $17 billion undersea rail tunnel that would link Helsinki, Finland, and Tallinn, Estonia; the project is backed by Finnish investor and “Angry Birds” entrepreneur Peter Vesterbacka.
Waterstudio will oversee the construction this winter of a floating subdivision near Malé, the capital of the Maldives, where 80 percent of the country is less than 3.5 feet above sea level. It is made up of simple, affordable housing for 20,000 people. Under the hulls there will be artificial coral to help support marine life. The buildings will pump cold seawater from the depths to power the air conditioning systems.
A rendering of a floating city planned for the Maldives, threatened by rising seas. (Source: Koen Olthuis, Waterstudio)
“There’s no longer this idea of a mad magician building a floating house,” Olthuis said. “Now we are creating blue cities, considering water as a tool.”
Floating homes, however, pose many challenges. High winds and thunderstorms, or even passing large cruise ships, can cause buildings to topple over. Schoonschip resident Siti Boelen said when she first moved in, the stormy weather made her think twice about venturing into her kitchen on the third floor, where she felt the most movement. “You feel it in your stomach,” she said, adding that she’s since gotten used to the feeling.
Floating homes also require additional infrastructure and work to connect to the electrical grid and sewage system, with special waterproof cords and pumps needed to connect to municipal services on higher ground. In the case of Schoonschip in Amsterdam and the floating office building in Rotterdam, new microgrids had to be built from scratch.
But the benefits can outweigh the costs. Rutger de Graaf, co-founder and director of Blue21, said the increasing number of disastrous and unprecedented storms around the world has prompted city planners and residents to look to water for solutions. Floating developments, he said, could have saved lives and billions of dollars in damage as recently as last summer, when deadly floods hit Germany and Belgium, killing at least 222 people.
“If there is flooding, many people are expected to move to higher ground. But the alternative is to stay close to coastal towns and explore expansion over water. “, explains De Graaf. “If you consider that in the second half of the century hundreds of millions of people will be displaced by sea level rise, we need to start now to increase the scale of floating developments.”