Hostile architecture

Hostile architecture is the design of built environments to restrict or discourage certain behaviors — typically those associated with vulnerable or unwanted populations. Benches with armrests that prevent lying down, spikes installed on window ledges to deter sitting, sprinklers timed to wet sleeping areas, and music played at frequencies unpleasant to young ears are all examples. The term was coined by critics of urban design to name what had previously been invisible: the use of architecture as a soft weapon of social control.

Hostile architecture operates through affordance theory in reverse. Where good design makes desirable actions easy, hostile design makes undesirable actions — from the perspective of property owners or city managers — difficult or impossible. The practice has been criticized as a form of spatial violence that displaces social problems rather than solving them, and as a demonstration that the built environment is never politically neutral.