Once you notice hostile architecture, it becomes impossible to ignore. This design approach, also known as hostile design or defensible architecture, is present throughout cities and public spaces across America, subtly discouraging certain behaviors and keeping specific groups of people away. From divided benches at bus stops to metal spikes under building awnings, these design elements are strategically placed to make people uncomfortable enough to leave or to prevent particular activities from taking place.
Anastasia Loukaitou-Sideris, a professor of urban planning and dean at UCLA's Luskin School of Public Affairs, explains the concept simply: "Through design you are making them uncomfortable so that they leave, or you're making particular activities that they tend to do uncomfortable." The most recognizable example is a bench divided into sections, typically designed to prevent someone from lying down. Even the construction of these benches, often featuring metal slats with gaps between them, provides enough comfort for brief sitting while discouraging extended stays.
Some transit stations have eliminated benches entirely, instead offering only surfaces for passengers to lean against while waiting. More obviously aggressive examples include metal spikes installed along sidewalks or under awnings to prevent people from sitting or lying on the ground. However, hostile architecture often takes more subtle forms that can be harder to identify at first glance.
In San Francisco, large steel planter bins were installed on sidewalks under the guise of beautification, but neighborhood residents recognized their true purpose: reducing space where people could set up tents. Another San Francisco neighborhood attempted a similar strategy using large boulders, though these were eventually removed following public criticism. Seattle's Department of Transportation once installed bike racks under an overpass in a location where bike parking wasn't needed, positioning them in a way that critics said was clearly designed to prevent tent setup. The city ultimately removed these bike racks as well.
Anti-skateboarding measures represent another category of hostile design. Metal bars or divots are frequently installed to interrupt long benches or railings, preventing skateboarders from using these surfaces for tricks. These interruptions serve no other functional purpose beyond deterring skateboard activity.
Hostile design extends beyond physical structures to include environmental tactics. Loukaitou-Sideris cites an example from Los Angeles: "There was a Skid Row park in Los Angeles where the authorities would start the sprinklers at night so people could not sleep in the park." Some businesses blast loud music outside their establishments to discourage gathering or extended loitering.
In recent years, discussions about hostile architecture have increasingly focused on homelessness issues, raising fundamental questions about public space design and accessibility. The debate presents complex perspectives on both sides. Loukaitou-Sideris explains one viewpoint: "You can consider bus stops public spaces because everybody can sit there and they should be open and accessible to the public, right? And unhoused people often use the bus – sometimes they use it as shelter but sometimes they use it to go to work, or reach a destination. So by excluding them from these spaces, does it retain the publicness of the bench?"
However, local governments often present a different perspective. As Loukaitou-Sideris notes, "Local governments would say that if the space is occupied constantly by an unhoused person, then other legitimate riders will not be able to use it." This represents the core tension in hostile architecture debates: balancing accessibility with intended use.
While homeless individuals are frequently the primary targets of hostile design, these measures affect everyone who uses public spaces. An uncomfortable bench remains uncomfortable for all users, not just those attempting to sleep on it. Steel planters or boulders that consume sidewalk space reduce walking room for everyone, including parents pushing strollers. Spikes installed under store awnings prevent anyone from seeking shelter from rain in those areas.
The hostile architecture debate spans over a century and continues in state legislatures, academic institutions, and online forums. What might appear to be minor design decisions actually encompass broader issues of discrimination, access to public resources, social control, and individual freedoms.
Selena Savic, co-editor of "Unpleasant Design," offers a critical perspective on the bench example in a 99 Percent Invisible podcast episode: "A classic is the bench with armrests in between, which of course let you rest your arm on the armrest, but at the same time they restrict any other kind of use than sitting upright. The only way this bench can be used is by three people sitting next to each, not looking at each other – which is not the only thing you can do on a bench. Especially, it's not the only normal and legal thing you can do on a bench."
Savic argues that by attempting to prevent sleeping on benches, designers may discourage all usage. She concludes with a broader criticism of the hostile design philosophy: "When we expect people to do bad things to the bench before we think of anything good that people might do to this bench, I think that's a very sad approach to public space." This perspective highlights how hostile architecture reflects assumptions about public behavior and who deserves access to shared urban spaces.
