Enemy Architecture

Exclusionary Architecture (Hostile Architecture) is an urban design strategy that deliberately restricts and controls the use of urban and public spaces for specific groups and behaviors.

Hostile architecture is regarded as one of the most visible tools for implementing social exclusion. Public spaces in modern cities are not only assessed for their architectural aesthetics but also as physical manifestations of social relations, power dynamics, and societal priorities. In this context, hostile architecture conveys silent yet definitive messages to city residents about “who is allowed to be here” and “who is not welcome.” Seemingly ordinary designs are in fact intended to exclude and render invisible certain social groups from urban life.

Representative Visual of Hostile Architecture (Generated by Artificial Intelligence)

Purpose of Hostile Architecture

The primary aim of hostile architecture is to restrict access to and modes of use in public spaces in order to prevent certain behaviors and deter long-term occupation by specific social groups. Urban administrators and designers justify these practices by citing reasons such as maintaining urban order, enhancing safety, and preserving the intended function of the space. In practice, these measures affect the activities of homeless individuals, youth, and other groups requiring prolonged rest. Thus, hostile architecture creates space for the city’s prioritized users while physically limiting certain uses.

The primary objective of this design approach is to make urban spaces orderly, aesthetic, and secure. These arrangements are implemented to balance competing uses within public areas. Details such as spiked metal protrusions on sidewalks, segmented benches, or sloped surfaces structure how space is utilized. Through these interventions, cities aim to provide an urban environment that serves designated functions.

The structural foundations of hostile architecture include the management of urban space and economic regulation. Within this governance framework, public space may prioritize consumption and economic activity. Movement, sitting, and resting activities in the city are organized to align with the primary economic functions of the space. The configuration of free public amenities is a strategy that influences how users move and pause within urban environments. Another dimension of this architectural approach is its connection to security and crime prevention policies.

Exclusionary designs are the product of an approach aimed at preventing unwanted or unlawful activities in public space. From this perspective, behaviors are treated as elements that threaten urban order. Streets, parks, and underpasses are physically reconfigured to deter potential violations. In this context, hostile architecture functions as a system that regulates patterns of behavior in the city through urban design tools.

Examples of Hostile Architecture

Hostile architecture is expressed not as a theoretical concept but through concrete examples observable in urban life. The common feature of these examples is their restriction of prolonged stay or overnight occupation in public spaces. Segmented benches in parks, obstructive elements placed under bridges, and uncomfortable surfaces designed to discourage sleeping on the streets are typical manifestations.

These architectural examples are oriented not only toward aesthetic and functional concerns but also toward behavioral control. In this context, urban design becomes a mechanism of regulation. Known examples of hostile architecture include segmented benches, pointed protrusions, sloped surface restrictions, and indirect access barriers. Each of these implements the same strategy in different forms: deterring unwanted long-term uses or activities from the space.

Segmented Benches

Segmented or armrest-equipped benches are among the most common examples of hostile architecture. Although presented as designed for “ergonomic” or “aesthetic” reasons, they are in fact constructed to prevent people from lying down or sleeping on them. For this reason, such designs are also called “unsleepable benches.” Some versions are sloped or lack backrests; others are narrow and made of hard materials. All these subtle differences make prolonged sitting uncomfortable.

Representative Visual of Hostile Architecture (Generated by Artificial Intelligence)

Spiked Protrusions / Spikes

Sharp metal protrusions placed under bridges, building entrances, or apartment exits are commonly used to prevent homeless individuals from sleeping in these areas. Known as “anti-homeless spikes,” these designs physically deter use of public space. Such practices have drawn significant public backlash in cities like London, Paris, and Rome, and in some cases have been removed following intervention by local authorities.

Representative Visual of Hostile Architecture (Generated by Artificial Intelligence)

Ghost Amenities

In some cases, exclusion is achieved not by adding new elements but by removing existing ones. The removal of benches, public fountains, or restrooms under the pretext of “maintenance” falls into this category. Such spaces quickly transform into “sterile” areas accessible only during limited hours and under constant surveillance. Thus, while public space appears open to all, it is in practice restricted in access.

Representative Visual of Hostile Architecture (Generated by Artificial Intelligence)

Surface Restrictions and Micro-Interventions

Another form of hostile architecture involves surface interventions. Altering sidewalk slopes, designing walls that make leaning difficult, or installing small metal protrusions (known as “pig ears”) to deter skateboarders are all included in this category. These designs compel individuals toward a single behavior—such as merely “passing through.” Through such practices, the city becomes a kind of behavioral laboratory, restricting how people stop, rest, or socialize.

Representative Visual of Hostile Architecture (Generated by Artificial Intelligence)

Indirect Methods and Aesthetic Camouflage

Hostile architecture does not always manifest as an explicit “prohibition.” Sometimes, an indirect mechanism of exclusion is created through aesthetic elements such as artworks, flower pots, or lighting and sound arrangements. For example, in some cities, classical music is played under bridges to discourage youth gatherings. In other areas, recycling bins are locked.

Representative Visual of Hostile Architecture (Generated by Artificial Intelligence)

Scope and Impacts of Hostile Architecture

Hostile architecture is an urban planning approach aimed at regulating the use of public space and restricting specific behaviors. By defining the conditions and modes under which urban space can be used, these practices structure access to and use of the city. As a result, urban space takes on a form that serves orderly use and supports designated behaviors.

One of the most prominent effects of this architectural approach is the regulation of activities by homeless individuals within the urban environment. Homeless people use public space not only as a transit point or resting area but also as a place for shelter and survival. Exclusionary designs restrict such prolonged or accommodation-oriented uses. Benches made uncomfortable for sleeping, metal plates covering heating grates, and physical barriers beneath bridges limit homeless individuals’ access to and use of urban spaces.

The impacts of hostile architecture are not confined to homeless people alone. These practices can indirectly affect elderly individuals, pregnant women, people with disabilities, and those with limited mobility. For example, sloped surfaces that prevent prolonged sitting do not merely deter loitering but also restrict the resting needs of older adults and other users. Divided benches or narrow seating areas make it difficult for wheelchair users or individuals with physical discomfort to benefit comfortably from public spaces.

Another significant consequence is that hostile architecture serves to render unwanted activities invisible within the urban landscape. Such designs reduce the visibility of certain problems in city centers. Removing homeless individuals from major public areas can lead to the displacement of their activities into more isolated locations.

Many urban residents may not directly perceive the restrictive function of these designs because hostile architecture is often presented under aesthetic or functional justifications. Armrests are described as “comfort features,” protrusions as “decorative details,” and planters as “landscape enhancements.” This implies that behaviors are shaped not by explicit prohibitions but by environmental configurations. Hostile architecture operates on this principle: it does not impose explicit “bans,” but rather defines “acceptable behavior” through the form of the space itself.

A key feature of this system is the public’s ability to perceive these practices as normal elements of urban design. Most city dwellers may interpret a metal partition on a bench as “designed for a better seating experience”; meanwhile, the design’s function of preventing long-term use by certain groups may go unnoticed. This enables exclusionary architecture to be readily accepted by public perception and integrated as a natural component of urban order.

Example of Bench Application in Urban Space (unsplash)

Conceptual Framework and Terminology

The concept of hostile architecture is described in academic literature using a range of closely related terms to define the practice of regulating specific behaviors and managing urban space. These different labels help clarify various dimensions of the design practice and their functions within urban order. Each term is grounded in the idea that urban space is intentionally designed to structure behavior, reinforce social norms, and regulate usage.

The academic terminology for this concept constitutes an interdisciplinary field of study. Disciplines such as urban planning, architecture, sociology, and criminology have examined this form of regulatory architecture from their own perspectives. Consequently, the terminology encompasses both the physical design and its sociopolitical contexts.

• Hostile Architecture (Hostile Design): The most commonly used term. It describes how urban design becomes a tool for restricting prolonged use and targeting the activities of specific groups, such as homeless individuals. This term emphasizes the active control function of design over urban behavior.
• Exclusionary Architecture: Refers to physical arrangements that limit social participation or prevent certain uses. This design functions as a form of power that shapes how space is used by denying access to specific activities.
• Defensive Architecture / Design: This term is often associated with security strategies. It represents an approach that treats urban space as a protective and regulatory measure against perceived threats.
• Disciplinary Architecture / Design: Denotes design approaches aimed at guiding and controlling behavior. In this context, architecture structures the movements and actions of users within space.
• Criminological Prevention Through Environmental Design (CPTED): One of the technical roots of hostile architecture. Developed in the 1970s, this approach is a security-focused urban planning strategy that aims to reduce “crime opportunities” through environmental modifications.

This terminological diversity reflects the multidimensional nature of the concept. Words like “hostile” and “exclusionary” emphasize the restrictive character of the design, while terms such as “defensive” and “CPTED” situate the practice within a technical and security-oriented framework.

Underpinnings of Hostile Architecture

The structural foundations of hostile architecture include the management of urban space and neoliberal economic policies. Neoliberal urban policies prioritize uses of public space that generate economic value. In this context, the city is structured as a space suited for the activities of productive and consuming individuals. The presence of homeless people is perceived as conflicting with the aesthetic integrity of the urban order, prompting architectural interventions to redirect them from public areas. The right to use public space is thus structured according to one’s capacity to align with urban order and economic activity.

This architectural logic links the concept of “security” to urban and economic regulation. Here, security encompasses not only physical threats but also the preservation of economic and aesthetic order. When cities seek to become attractive for capital accumulation and tourism, visible signs of poverty can be treated as a "risk."

Another aspect of hostile architecture is its relationship with security and crime prevention policies. Exclusionary designs are the product of an approach aimed at preventing unwanted or unlawful activities in urban spaces. Prolonged sitting by an individual, a group gathering in a park, or a homeless person sheltering under a bridge are all perceived as potential “pre-disorder conditions.” This perception transforms design into a form of preventive control mechanism: spatial conditions are arranged to prevent unwanted uses before they can emerge.

The security paradigm also brings with it a process of regulating behavior. Human actions such as resting, sitting, or waiting can be perceived as “disorderly” when performed in inappropriate locations. Thus, hostile architecture becomes part of an urban order that codes not only illegal activities but also specific behavioral patterns as deviant. The tranquility and apparent cleanliness and silence of the city are achieved through the regulation of urban space usage.

Ethical Frameworks and Social Perceptions

Hostile or exclusionary architecture is not merely a matter of urban design; it is also a subject of moral, social, and political debate. This is because such practices raise fundamental ethical and human questions regarding the right to use space and who is entitled to visibility in the city.

A widely criticized aspect of hostile architecture is that it raises concerns about human dignity and spatially reflects social inequality. Design elements such as metal protrusions preventing sleeping or benches designed to discourage sitting are seen as physical constraints and evaluated as ethically questionable practices.

Hostile architecture is often justified on grounds of “enhancing security” or “maintaining public order.” Here, the concept of security encompasses not only physical threats but also aesthetic and order-related perceptions. This perspective distinguishes between “appropriate” and “inappropriate” uses of urban space. The activities of elderly people, migrants, or homeless individuals may be perceived as “disrupting public peace.”

Critics argue that hostile architecture is a consequence of neoliberal urbanization. In this framework, the city functions less as a space for public life and more as a venue designed to facilitate capital circulation. Spaces are organized for investors and consumers; uses that are unproductive or incompatible with consumption are excluded from these areas.

In this context, hostile architecture functions as a mechanism of restriction on the use of urban space. City centers are designed for economic activity, and the visibility of groups that do not contribute economically is reduced by redirecting them to peripheral areas. Due to the prioritization of commercial use over public space, free benches or seating areas may be removed and replaced with private cafés or paid facilities. Defenders of hostile architecture claim that these designs make the city “more aesthetic” and “more orderly.” This aesthetic vision seeks to present the city as a regulated and controlled environment.

Representative Visual of Hostile Architecture (Generated by Artificial Intelligence.)

Global Spread of Hostile Architecture

Although hostile architecture initially appeared as a local design trend in certain Western metropolises, it has gradually become a standardized urban policy on a global scale. These practices are justified through factors such as homelessness, migration, security concerns, or urban aesthetics.

Los Angeles: Fountains, sloped benches, and spiked seating areas have been widely used to deter homeless individuals.

New York: Barriers preventing sitting in public spaces, protrusions along flower beds, and “anti-skateboard” surfaces are common. In subway stations, armrests on benches and uncomfortable surfaces prevent prolonged sitting.

Atlanta and Cincinnati: Legal regulations—banning loitering in Atlanta and prohibiting lying on sidewalks in Cincinnati—have completed the spatial dimension of hostile architecture.

Seattle: Practices such as the removal of trailer parks have been interpreted as examples of social exclusion disguised under the pretext of environmental regulation.

Toronto: The #DefensiveTO hashtag, created to document hostile architecture, has led to the mapping of such practices across the city.

Montreal: Skateboard deterrents and specialized security barriers are common.

Vancouver: The removal of areas where homeless people can sleep at night has generated social tension in the city.

United Kingdom: Benches described as “anti-homeless spikes” and “comfort-rejecting” furniture can be found.

Denmark: At Copenhagen Central Station, disciplinary acoustic measures such as loud classical music are employed, and anti-urination spikes are installed around Tivoli.

France: In Paris, stone blocks have been placed under bridges and in squares to deter homeless people; in Calais, large boulders have been positioned in public spaces to prevent migrants from setting up camps.

Belgium: In Brussels, “modern deterrence” tools such as armrests on metro station benches and sharp metal protrusions in front of shops are used.

Spain: Seating areas have been removed in Barcelona, while protests have been held in Madrid against anti-homeless benches.

Italy: Campaigns have been launched in Rome against anti-homeless devices installed on public benches.

Japan: In metropolises such as Tokyo and Osaka, benches designed to prevent sitting and barriers installed under bridges are widespread.

Türkiye: Practices such as removing banks in Kızılay, Ankara, and replacing them with metal barriers are examples of the regulatory function of urban design.