Could floating shipping containers help sort out the world’s slums?

The interior of the first completed City App. Image: Waterstudio.NL.

“What if a city was as flexible as a shuffle puzzle?” Koen Olthuis asked in his 2012 TEDx talk. He was referring to those games in which you move squares around until you make a picture. At the time, his audience probably didn’t realise he was serious.

But using moveable little boxes to meet a city’s needs were exactly what Olthuis was proposing. His talk was on the subject of the “Floating City Apps” developed by his architectural firm, the Netherlands-based Waterstudio. (You may remember them from their plans for a floating golf course in the Maldives. Or maybe you saw their designs for a snowflake-shaped hotel off the coast of Norway.)

These mobile buildings would float on bodies of water at the edges of cities. They could also be moved around according to a city’s needs, and could fulfil a range of different functions. Some would be educational, with internet access and computers; others could act as bakeries, housing, healthcare centres, or floating mats of solar panels. 

In June, the first piece of Olthuis’ shuffle puzzle was completed: an educational suite which will double up as an internet cafe in the evenings, all powered by solar panels on its roof. It’s been built inside a shipping container, to makes it easy to transport; a base constructed from thousands of plastic bottles collected by slum residents will be added once it reaches its destination.

It’s due to be shipped out to a slum in Manila in the autumn. Here’s the architect’s mock-up of the city app in situ:

Olthuis’ interest in water-based construction was inspired partly by his home country: around half the Netherlands lies below sea level, and massive amounts of water are pumped away daily to keep the country high and dry. But it’s not the low countries that could benefit most from this kind of architecture: it’s the rapidly growing and slum-packed cities of the developing world, and wet slums – those edging onto bodies of water, and so at risk of rising sea levels – were forefront in Olthuis’ mind when he came up with the idea:

“They’re some of the hardest areas to help, because they’re so close to the water,” he says. “People are unwilling to invest in development that could flood, or just wash away.” His hope is that these City Apps could help change that: the units they would rise with sea levels if an area floods, and could be moved elsewhere if necessary. This first app was funded by the prize money from the 2012 Architecture and Sea Level Rise Award, the studio and other sponsors; in future, the studio is hoping to build them then lease them out to NGOs and development agencies for a low monthly cost.

There’s a case for helping the world’s 1.1bn slum dwellers to more permanent settlements, rather than just improving the slums, of course. But in Olthuis’ view, “slums aren’t going to go away, so the only thing we can do is upgrade their prosperity”. There are a few creases to iron out first, though – at the moment, the studio may have to pay tax on transporting the Manila app, and are meeting with embassies to try and avoid this “real waste of money”. 

While the city app will be run by a local organisation once in Manila, Olthuis is keen to stay involved. “The most important thing is that we can measure the app’s effects, and check how it’s working.” He wants to build hundreds, even thousands, more apps for different purposes around the world: 90 per cent of the world’s largest cities border a body of water, whether it be river, lake, or sea, so the project’s applications could stretch far beyond wet slums. Because of their floating foundations, the apps are relatively stable, though they may not work so well in waters prone to violent waves.

For Olthuis, floating architecture offers a way to use the dead space off the coasts of cities. It also offers flexibility, as units can be moved to a different location, or even another city, as the needs of the surrounding area change – just as you can change the apps on your phone.

Image: architect Koen Olthuis at Waterstudio.NL.


CityMetric is now City Monitor! Come see us at our new home

City Monitor is now live in beta at

CityMetric is now City Monitor, a name that reflects both a ramping up of our ambitions as well as our membership in a network of like-minded publications from New Statesman Media Group. Our new site is now live in beta, so please visit us there going forward. Here’s what CityMetric readers should know about this exciting transition.  

Regular CityMetric readers may have already noticed a few changes around here since the spring. CityMetric’s beloved founding editor, Jonn Elledge, has moved on to some new adventures, and a new team has formed to take the site into the future. It’s led by yours truly – I’m Sommer Mathis, the editor-in-chief of City Monitor. Hello!

My background includes having served as the founding editor of CityLab, editor-in-chief of Atlas Obscura, and editor-in-chief of DCist, a local news publication in the District of Columbia. I’ve been reporting on and writing about cities in one way or another for the past 15 years. To me, there is no more important story in the world right now than how cities are changing and adapting to an increasingly challenging global landscape. The majority of the world’s population lives in cities, and if we’re ever going to be able to tackle the most pressing issues currently facing our planet – the climate emergency, rising inequality, the Covid-19 pandemic ­­­– cities are going to have to lead the way.

That’s why City Monitor is now a global publication dedicated to the future of cities everywhere – not just in the UK (nor for that matter just in the US, where I live). Our mission is to help our readers, many of whom are in leadership positions around the globe, navigate how cities are changing and discover what’s next in the world of urban policy. We’ll do that through original reporting, expert opinion and most crucially, a data-driven approach that emphasises evidence and rigorous analysis. We want to arm local decision-makers and those they work in concert with – whether that’s elected officials, bureaucratic leaders, policy advocates, neighbourhood activists, academics and researchers, entrepreneurs, or plain-old engaged citizens – with real insights and potential answers to tough problems. Subjects we cover include transportation, infrastructure, housing, urban design, public safety, the environment, the economy, and much more.

The City Monitor team is made up of some of the most experienced urban policy journalists in the world. Our managing editor is Adam Sneed, also a CityLab alum where he served as a senior associate editor. Before that he was a technology reporter at Politico. Allison Arieff is City Monitor’s senior editor. She was previously editorial director of the urban planning and policy think tank SPUR, as well as a contributing columnist for The New York Times. Staff writer Jake Blumgart most recently covered development, housing and politics for WHYY, the local public radio station in Philadelphia. And our data reporter is Alexandra Kanik, whose previous roles include data reporting for Louisville Public Media in Kentucky and PublicSource in Pittsburgh, Pennsylvania.

Our team will continue to grow in the coming weeks, and we’ll also be collaborating closely with our editorial colleagues across New Statesman Media Group. In fact, we’re launching a whole network of new publications, covering topics such as the clean energy transition, foreign direct investment, technology, banks and more. Many of these sectors will frequently overlap with our cities coverage, and a key part of our plan is make the most of the expertise that all of these newsrooms combined will bring to bear on our journalism.

Please visit going forward, where you can also sign up for our free email newsletter.

As for CityMetric, some of its archives have already been moved over to the new website, and the rest will follow not long after. If you’re looking for a favourite piece from CityMetric’s past, for a time you’ll still be able to find it here, but before long the whole archive will move over to City Monitor.

On behalf of the City Monitor team, I’m thrilled to invite you to come along for the ride at our new digs. You can follow City Monitor on LinkedIn and on Twitter. If you’re interested in learning more about the potential for a commercial partnership with City Monitor, please get in touch with our director of partnerships, Joe Maughan.

I want to thank and congratulate Jonn Elledge on a brilliant run. Everything we do from here on out will be building on the legacy of his work, and the community that he built here at CityMetric. Cheers, Jonn!

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Sommer Mathis is editor-in-chief of City Monitor.