Hostile architecture

Hostile architecture is an urban-design strategy that uses elements of the built environment to purposefully guide or restrict behaviour. It often targets people who use or rely on public space more than others, such as youth and homeless people, by restricting the physical behaviours they can engage in.[1]

Bolts installed in the front steps of a building to discourage sitting and sleeping

Also known as defensive architecture, hostile design, unpleasant design, exclusionary design, and defensive urban design, the term hostile architecture is often associated with "anti-homeless spikes" – studs embedded in flat surfaces to make sleeping on them uncomfortable and impractical. This form of architecture is most commonly found in densely populated areas.[2][3] Other measures include sloped window sills to stop people sitting; benches with armrests positioned to stop people lying on them; water sprinklers that "intermittently come on but aren't really watering anything"; public trash bins with inconveniently small mouths to prevent the insertion of bulky wastes; cold-water-only taps in public toilets (with running-time limits so that they need to be activated repeatedly); fluffy and sticky thin toilet paper to prevent the clogging of toilet sewers.[4][5] Hostile architecture is also employed to deter skateboarding, littering, loitering, and public urination.


Although the term "hostile architecture" is recent, the use of civil engineering to achieve social engineering is not: antecedents include 19th century urine deflectors.[6][7] Its modern form is derived from the design philosophy Crime Prevention through Environmental Design (CPTED), which aims to prevent crime or protect property through three strategies: natural surveillance, natural access control, and territorial enforcement.[8]

Consistent with the widespread implementation of defensible space guidelines in the 1970s, most implementations of CPTED as of 2004 were based solely upon the theory that the proper design and effective use of the built environment can reduce crime, reduce fear of crime, and improve quality of life. Built environment implementations of CPTED seek to dissuade offenders from committing crimes by manipulating the built environment in which those crimes proceed from or occur. The six main concepts according to Moffat are territoriality, surveillance, access control, image/maintenance, activity support and target hardening. Applying all of these strategies is key when trying to prevent crime in any neighborhood, crime ridden or not.[9]

Boulders installed along a freeway ramp in Portland, Oregon, United States as a hostile architecture to deter transient camps.


The "Camden bench", used in London, has a design that is stated to discourage sleeping, littering, skateboarding, drug dealing, graffiti and theft

Camping deterrentEdit

  • Anti-homeless spikes in London, England to prevent homeless activity.[10]
  • Seattle, Washington, United States city government installed bicycle racks to prevent homeless people from camping.[11][12]
  • Since 2013, the Oregon Department of Transportation in Oregon, United States deployed large boulders at eight locations that had been the site of transient camps in Portland. These boulders were installed to deter illegal camping near the freeways.[13]

Sleeping deterrentEdit

Camden Borough Council in London commissioned concrete-block benches (dubbed "Camden benches") designed to discourage uses such as sleeping, skateboarding and placing stickers.[6][14]

Urination deterrentEdit

A urine deflector is a device for deflecting the stream of urine during urination. These may be part of a chamber pot, latrine or toilet intended for the purpose, or they may be deterrents. They may be constructed in various ways from a variety of materials but are typically designed to have an angled surface which catches and redirects the stream.

Public receptionEdit

Opponents to hostile architecture in urban design states that such architecture makes public spaces hostile to the public themselves and especially targets the transient and homeless populations.[15] Proponents say it is necessary to maintain order and safety and deter unwanted behaviors such as sleeping, loitering and skateboarding.[citation needed]

In 2018, British artist Stuart Semple created a social media public awareness campaign encouraging the public to place identifying stickers on instances of hostile design in their environment.[16][17][18]

Examples of hostile architecture circulating within UK media have led to negative reception. The Joseph Rowntee Foundation warned that homelessness in London is rising significantly faster than the nationwide average.[citation needed] Nonetheless, types of hostile architecture have increased. For example, Selfridges in Manchester installed metal spikes outside for the purpose of reducing “litter and smoking," which suggests hostile architecture may be implicated for one reason but explained by another.[19]


See alsoEdit


  1. ^ Chellew, Cara (2019). "Defending Suburbia: Exploring the use of defensive urban design outside of the city centre". Canadian Journal of Urban Research. 28: 19–33.
  2. ^ Omidi, Maryam (12 June 2014). "Anti-homeless spikes are just the latest in 'defensive urban architecture'". The Guardian. Retrieved 23 February 2015.
  3. ^ Andreou, Alex (18 February 2015). "Anti-homeless spikes: 'Sleeping rough opened my eyes to the city's barbed cruelty'". The Guardian. Retrieved 23 February 2015.
  4. ^ Quinn, Ben (13 June 2014). "Anti-homeless spikes are part of a wider phenomenon of 'hostile architecture'". The Guardian. Retrieved 23 February 2015.
  5. ^ Mills, Chris (21 February 2015). "How 'Defensive Architecture' Is Ruining Our Cities". Retrieved 23 February 2015.
  6. ^ a b Swain, Frank (2 December 2013). "Secret city design tricks manipulate your behaviour". BBC.
  7. ^ Lee, Jackson (23 July 2013). "Urine Deflectors in Fleet Street". The Cat's Meat Shop. Retrieved 23 February 2014.
  8. ^ Chellew, Cara (2016). "Design Paranoia". Ontario Planning Journal. 31 – via ResearchGate.
  9. ^ Wilson, Paul (1989). Designing Out Crime. Australian Institute of Criminology. p. 23.
  10. ^ Andreou, Alex (2015-02-18). "Defensive architecture: keeping poverty unseen and deflecting our guilt". The Guardian. ISSN 0261-3077. Retrieved 2020-07-25.
  11. ^ Groover, Heidi (19 December 2017). "Seattle Uses Bike Racks to Discourage Homeless Camping". The Stranger. Retrieved 17 December 2017.
  12. ^ "New anti-homeless architecture: Seattle uses bike racks to block rough sleepers". the Guardian. 2018-01-24. Retrieved 2020-07-25.
  13. ^ Kruzman, Diana (2019-07-04). "Portland's homeless campers face new obstacle: piles of boulders". oregonlive. Retrieved 2020-07-25. The boulders are a form of hostile architecture or defensive design
  14. ^ "The Camden Bench". Ian Visits. 2 December 2016.
  15. ^ Hu, Winnie (November 8, 2019). "'Hostile Architecture': How Public Spaces Keep the Public Out". The New York Times. ISSN 0362-4331. Archived from the original on September 3, 2020. Retrieved November 12, 2020.
  16. ^ Wallace, Elizabeth. "What's Behind the Uptick in Hostile Architecture?". Architectural Digest. Retrieved 2020-07-25.
  17. ^ "Stuart Semple launches campaign to eradicate 'hostile design' around the world". Retrieved 2018-02-15.
  18. ^ "Artist Launches Campaign to Call Out Hostile Urban Design". Hyperallergic. 2018-02-01. Retrieved 2018-02-15.
  19. ^ "Defensive architecture: keeping poverty unseen and deflecting our guilt". the Guardian. 18 February 2015.

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