Putting Cities’ Abandoned Spaces To Work—Fighting Climate Change

Local Code takes thousands of underused urban spaces and optimizes them to fight flooding, heat, and extreme weather.

Putting Cities’ Abandoned Spaces To Work—Fighting Climate Change

City infrastructure–like sewer pipes, for instance–are built to accommodate a certain number of people, and withstand a certain amount of bad weather. But with climate change heralding higher temperatures and larger storms and more unexpected weather events, American cities’ 19th century infrastructure will only be resilient up to a point.


But what if you could create a network of sites across a city, that together could mitigate particular ecological threats, from sudden storm waters to heat waves? What if you could use a computer program to create thousands of site-specific designs for abandoned land in that city, maximizing its positive ecological impact?

That’s what Nicholas de Monchaux has done. The UC Berkeley professor of urban design and architecture has spent the last six years working on a project called Local Code. He has mapped thousands of underused sites in four different cities–starting with San Francisco, followed by Los Angeles, New York, and Venice, Italy–and has written code to connect each specific location with a design proposal to transform it into a point of urban resilience. The proposals would fill these abandoned sites with greenery, bioswales, porous paving, and low albedo surfaces–all established techniques for increasing urban resilience and improving the ecology of a city.

In October, his findings–in the form of 3,659 individual, site-specific design proposals and several complementary essays–were published in the book Local Code by the Princeton Architectural Press.

But getting to this point took six years of work, combing through cities for underutilized spaces below billboards, in alleys, and in vacant lots. Here’s how he did it.



Mapping Cities’ Dead Spaces

The project began when de Monchaux heard about San Francisco’s Department of Public Works has a database of over 1,500 parcels of land that are zoned as streets but aren’t actually maintained by the city. They’re called “unaccepted streets”–you can’t build on them, so they just become abandoned pockets of land that detract from their neighborhood.

De Monchaux tracked down the spreadsheet of unaccepted streets, and with the blessing of the city’s mayor, created the first map documenting all of them. After seeing these dead-end alleys laid out, de Monchaux realized that they were mostly located in the hottest, most polluted, most flooded, and poorest parts of the city–neighborhoods which have little access to public space or infrastructural resources.

The combined area of the proposed sites in San Francisco is about 500 acres, about two-thirds the size of Golden Gate Park. Yet, if you took that 500 acre piece of land and instituted the same kinds of ecological interventions within it, de Monchaux says, it would have a marginal impact on the environmental health of the city. An infrastructural network of connected parts will be much more effective in helping the city handle extreme weather.

Take flooding. In California, it might not rain for six to eight months, but when it does, the rainfall can be torrential, potentially overloading the underground sewer and storm water systems–which get backed up if only one point in the system fails. San Francisco recently signed a $1.5 billion bond to overhaul its sewage system that, de Monchaux claims, simply aims to take the existing pipes out of the ground and replace them with bigger ones. He proposes that the city invest that same money in a distributed way, using the city’s unaccepted streets. “Because of where these vacant lots are–which is true in all the cities we looked at–you couldn’t pick better acupuncture points,” he says. “There’s a multiplying power to the investment because of where these things are located.”

In Los Angeles, de Monchaux focused his idea for this distributed network of resilient infrastructure on the unused land under billboards. Owned by billboard companies, this land might be turned into parking lots, he says, but mostly it lies fallow and unused. Because these pockets of cityscape are frequently located along freeways, where the poorest neighborhoods of LA also happen to be, these spaces could be used to provide social and political resilience to the people who live near them as well. He paired with the nonprofit Amigos De Los Rios, which works to similarly transform these overlooked spaces and already had a database of 150 sites. Using crowdsourcing, de Monchaux was able to map a total of 786 sites, forming the basis for the Los Angeles case study. Meanwhile, in New York, he worked with the Urban Ecology Lab at the New School and the nonprofit Green City Force. The Urban Ecology Lab had already catalogued 30,000 vacant lots in the city and scouted 1,500 of them–which became the basis for the New York case study.


When the project was featured in the American pavilion at the 2012 Venice architecture Biennale, de Monchaux was asked to do a case study for the Italian city, whose ecological problems have been well documented. He responded by mapping the abandoned islands in the Venetian lagoon, proposing the restoration of the area’s natural marshy ecology–which absorbs flood water much more effectively than the current man-made flood barrier.

De Monchaux says that the islands could act as catalytic points from which the wetlands are regrown, and in coordination with filling in some of the shipping channels, the ecology of the lagoon and the city’s natural defense against flooding could be rebuilt.

Coding Resilience

After mapping thousands of abandoned sites, de Monchaux’s next step was to design the best infrastructural and ecological use for each. And the most effective way to do that was to connect his GIS mapping software and parametric design software. But there weren’t any design tools out there that could stand up to the task–so with the help of the Berkeley Center for New Media (of which he is the director) and a residency program at the software company Autodesk, de Monchaux wrote his own. He calls it a “software pipeline” between the two existing programs. “It’s the same as any design problem, but your design intelligence is being spread in a completely new way across many different sites,” he says.

The open-source software, now available for anyone to use on Github, takes a set of parameters–like the amount of stormwater, the material and condition of the surrounding buildings, the location of nearest sewer pipe and how much it can handle–and spits out a site-specific design for the space. Using the program, de Monchaux can test the effects of different kinds of designs on the dataset. “Instead of saying we’re going to put green things anywhere, we’re using the power of digital design tools to actually place individual elements on each site where they can do the most ecological good,” he says.

For instance, it doesn’t make sense to install materials that absorb solar radiation where the sun rarely shines. De Monchaux’s tool instead figures out where the sun shines on every single site and where the most solar radiation hits over the course of a year. Those then become the ideal location for loams and plants. Another example: The software can build a flow model of storm water, tracking where the water comes from and where it goes, as well as where the existing storm sewer is located. Then, it recommends that a stormwater retention device like a bioswale be placed between the source and destination, slowing down the water as it moves towards the sewer system.


It took six years for de Monchaux to develop the code that would support the program’s many, many different parameters and situations. And even so, the design relationships don’t work for 5% of the sites. But the bigger challenge? Any of these designs are only starting points for conversations within the local communities. The software, of course, doesn’t take in account social or political factors, mostly because those are difficult to model.

“You couldn’t maximum design for social impact, but you can for the flow of water,” he says. Instead, Local Code attempts to show how much can be accomplished with this new kind of framework, using the power of data and computers.

Better Software For Better Cities

While de Monchaux views the publication of the book as a landmark in the project, it’s not over yet. He believes that combining public funding for infrastructure with that spent on communities would be most effective, but these two elements of civic life are separately funded, complicating the process of building the proposals. “The book is a way to get the design portion of the work into the world and change people’s ways of thinking,” he says. “It’s a tool in the larger policy fight to change the conversation around infrastructure, connecting ecological resilience to economic and social resilience as well.”

The project is an example of using data to drive design, something de Monchaux believes will be increasingly common. And already, other designers are using the code. De Monchaux says he’s been approached by landscape architects who are doing work on even one site but want a way to connect underlying GIS data about the environment to parametric design tools. Another designer reached out to him about using the code for something entirely different–making jewelry for different sizes and shapes of bodies, and using the software to handle the multiple design iterations.

And he’s used it himself: In collaboration with Stamen Design in San Francisco and the Santa Fe Institute, de Monchaux used the software to develop a tool to find the best ways to build streets into informal settlements or favelas while demolishing the fewest houses.


The next step is to make these tools more usable and straightforward to support a community of users around the world, leveraging the power of the machine to create design solutions for the 21st century.

About the author

Katharine Schwab is the deputy editor of Fast Company's technology section. Email her at and follow her on Twitter @kschwabable