Dutch are turning to floating homes in the face of a wetter future

This story was originally published by Yale Environment 360 and appears here as part of the Climate desk Cooperation.

When a severe storm struck in October, residents of the Schoonschip floating community in Amsterdam had little doubt that they could weather it. They tied their bikes and outside benches, checked in with the neighbors to make sure they all had enough food and water, and crouched as their neighborhood slid up and down on their steel pillars, rising with the water, and after the rain subsided.

“We feel safer in a storm because we are floating,” said Siti Boelen, a Dutch television producer who moved into Schoonschip two years ago. “I find it strange that building on water is not a priority worldwide.”

When sea levels rise and charged storms make the water swell, floating neighborhoods offer a flood control experiment that could enable coastal communities to better cope with climate change. In the small but densely populated Netherlands, the demand for such houses is growing. And as more and more people want to build on the water there, officials are working to update the zoning laws to make it easier to build floating homes.

“The municipality wants to expand the concept of floating because it is a multifunctional use of living space and because the sustainable way is the right way,†said Nienke van Renssen, Amsterdam City Councilor of the Green Left.

The floating communities in the Netherlands that have emerged over the past decade have served as a proof of concept for larger projects that are now being led by Dutch engineers – not just in European countries like the UK, France and Norway, but in other countries as well. when French Polynesia and the Maldives were hurled, the Indian Ocean nation is now faced with an existential threat from rising sea levels. There is even a proposal for floating islands in the Baltic Sea on which to build small towns.

A floating house can be built on any coastline and is able to handle rising sea levels or rain-induced flooding by floating on the surface of the water. Unlike houseboats, which can be easily detached and relocated, floating houses are pinned to the shore, often resting on steel poles, and usually plugged into the local sewer system and power grid. They are structurally similar to houses built on land, but instead of a basement they have a concrete hull that serves as a counterweight and thus remains stable in the water. In the Netherlands, these are often prefabricated, square, three-story townhouses built off-site using conventional materials such as wood, steel and glass. For cities facing increasing flooding and a lack of building land, floating homes are a potential blueprint for expanding urban housing in the age of climate change.

Koen Olthuis, who founded Waterstudio in 2003, a Dutch architectural firm that focuses exclusively on floating buildings, said the relatively technically undemanding nature of floating houses may be their greatest asset. The houses he designed are stabilized by rods dug about 65 meters into the ground and equipped with shock-absorbing materials to reduce the feeling of movement from nearby waves. Houses rise when the water rises and sink when the water recedes. But despite their apparent simplicity, Olthuis claims they have the potential to transform cities in ways that have not been seen since the inception of the elevator that propelled the skylines up.

“We now have the technology, the ability to build on the water,” said Olthuis, who designed 300 floating houses, offices, schools and health centers. He and his colleagues added that he and his colleagues “see themselves not as architects, but as city doctors and see water as medicine”.

In the Netherlands, a country that is largely built on reclaimed land and one third of which is below sea level, the idea isn’t that far-fetched. In Amsterdam, which has nearly 3,000 officially registered traditional houseboats on its canals, hundreds of people have moved in floating homes in previously neglected neighborhoods.

Schoonschip, designed by the Dutch company Space & Matter, consists of 30 houses, half of which are maisonettes, on a canal in a former production area. The neighborhood is a short ferry ride from central Amsterdam, where many of the residents work. Community members share almost everything, including bikes, cars, and groceries bought from local farmers. Each building operates its own heat pump and uses around a third of its roof for green spaces and solar panels. The residents sell surplus electricity to each other and to the national electricity grid.

“Life on the water is normal for us, and that’s the point,” said Marjan de Blok, a Dutch television director who initiated the project in 2009 by organizing the collective of architects, legal experts, engineers and local residents that worked on it worked to project the water to get out of the ground.

Rotterdam, which is 90 percent below sea level and the location of the largest port in Europe, is home to the largest floating office building in the world, as well as a floating farm where cows are milked by robots to supply local grocery stores with dairy products. 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 establish such projects and has made floating buildings one of the pillars of its climate and adaptation strategy.

“In the last 15 years we have reinvented ourselves as a Delta City,†said Arnoud Molenaar, Chief Resilience Officer of the City of Rotterdam. “Instead of just seeing water as an enemy, we see it as an opportunity.”

To protect cities from climate change, the Dutch government launched its “Room for the River†program in 2006, which allows strategic areas to flood plains during heavy rain. Olthuis says the housing shortage in the Netherlands could boost demand for floating houses, including in “room for the river†areas where flooding will be part of the landscape for at least part of the year. Experts say that to alleviate the housing shortage in the Netherlands, one million new homes will need to be built over the next 10 years. Floating homes could help to compensate for the lack of developable land.

Dutch firms specializing in floating buildings have been inundated with requests from developers abroad to undertake more ambitious projects. Blue21, a Dutch technology company focused on floating buildings, is currently working on a planned series of floating islands in the Baltic Sea that will house 50,000 people and will be linked by a privately funded € 15 billion underwater railway tunnel, the Helsinki , Finland and Tallinn, Estonia; The Finnish investor and “Angry Birds†entrepreneur Peter Vesterbacka is behind the project.

Waterstudio will oversee the construction of a floating housing estate this winter near the Maldives’ low-lying capital, Male, where 80 percent of the land is less than a meter above sea level. It consists of simply designed, affordable living space for 20,000 people. Artificial corals are placed under the hulls to support marine life. The buildings will pump cold seawater from the depths to power air conditioning systems.

Planned floating city in Maldives threatened by rising sea levels.

“The idea of ​​a crazy magician building a floating house no longer exists,” said Olthuis. “Now we are creating blue cities and seeing water as a tool.”

However, floating houses present numerous challenges. Heavy winds and rain or even large cruise ships passing by can shake the buildings. Siti Boelen, the resident of Schoonschip, said that the first time she moved in, the stormy weather made her think twice before venturing into her kitchen on the third floor, where she felt the movement most. “You can feel it in your stomach,” she said, adding that she had got used to the feeling by now.

Floating homes also require additional infrastructure and labor to connect to the power grid and sewer system, requiring special waterproof cables and pumps to connect to community services at higher elevations. 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 growing number of devastating, unprecedented storms around the world has led both city planners and local residents to seek solutions in the water. Floating developments, he said, could have saved lives and prevented billions in damage last summer when fatal floods killed Germany and Belgium and killed at least 222 people.

“When floods occur, it is expected that many people will move to higher areas. But the alternative is to stay close to coastal towns and explore the expanse of water, â€says De Graaf. “When you consider that in the second half of the century hundreds of millions of people will be displaced by sea level rise, we must start now to increase the scale of the floating developments.”