Defensible space policies championed by right-wing politicians in the '70s and '80s continue to alienate people in low-income areas and blight our public spaces, writes Anna Minton.

Margaret Thatcher is not best-known for her contribution to design, but more than 30 years after she left office her stamp on the city remains. It's there in the ubiquitous bollards, gates and fences that define the contemporary British urban space. Today all the UK's public buildings and places, including parks, plazas, housing, schools, hospitals and official buildings embed high security and are designed around the principles of defensible space that she championed.

Mies van der Rohe famously described architecture as "the will of an epoch translated into space" and defensible space design policy, which emerged in the US in the 1970s, was twinned from the outset with the agenda of the New Right. The drive to "design out" crime promoted individualism, private space and territoriality over the inherently inclusive and collective nature of public space.

Defensible space design policy was twinned from the outset with the agenda of the New Right

In her memoirs, Thatcher describes how she became a "great admirer" of the academic geographer Alice Coleman, who had spent time in the US researching defensible space and whose work reflected a self-proclaimed fight against socialism. According to a new book on the subject, Defensible Space on the Move by Loretta Lees and Elanor Warwick, Coleman was the instrumental force behind the transportation from America to Britain of defensible space policies and the introduction of Secured by Design, the UK police-backed design initiative. The book explains how Coleman managed to secure a meeting with Thatcher where the two formed an immediate bond, resulting in £50 million of funding to implement her ideas.

The concept of defensible space was first popularised by Canadian architect Oscar Newman. His ideas originated with research on crime and violence in three housing projects in New York which, he claimed, proved that "territoriality" created space that could defend itself. By marking out boundaries clearly, he contended, residents would feel a sense of ownership over places, encouraging them to look after their patch and discouraging strangers and opportunistic criminals from entering.

Newman's ideas were criticised in the US for their environmental determinism and the view that design, rather than complex social problems, was responsible for crime. Nevertheless, chiming with the individualism of the time, they swiftly took off, with Newman appointed a high-level advisor to the US government. Meanwhile, in the UK, Coleman tried to persuade the Department of Environment of the merits of his approach but – until she caught Thatcher's attention – she was rebuffed, as civil servants felt that the research was simplistic. They believed instead that the issue of crime on housing estates required long-term, non-design interventions.

Undeterred, Coleman carried out her own research, based on the mapping of design features with "lapses in civil behaviour" such as litter, vandalism and excrement. Her 1985 book, Utopia on Trial, was excoriated by critics but its seemingly scientific approach strongly appealed to Thatcher.

Poor areas in particular become characterised by militarised levels of security

In the US, defensible space policies were realised by the policy of Crime Prevention Through Environmental Design (CPTED). Its British equivalent, Secured by Design, created security-based design standards and led to police officers being trained as crime-prevention design advisors.

Although the research began on housing estates, today planning permission for all public buildings, housing and schools in Britain depends on meeting Secured by Design standards, routinely characterised by high fences, gates, walls and bollards. Even benches are seen as potentially providing opportunities for anti-social behaviour.

The scheme is a private-public partnership between the police and the private security industry, with the Secured by Design website including a "members and products" section that links to security products ranging from security bollards to roller shutters and grilles, electronic locking systems and, of course, CCTV.

Poor areas in particular become characterised by militarised levels of security because the starting point for Secured by Design is a crime-risk assessment for the local area. Deprivation correlates with higher crime, and therefore is prescribed alienating high levels of security.

Lees and Warwick claim that defensible space has passed its high watermark and is slowly being removed from planning policy documents, with inclusive design once again taking precedence.

That is reflected by policy rhetoric, but it is not borne out by the visual evidence of our high-security, sterile public places, or the countless examples of the continuing heavy-handed approach of Secured by Design. There was recently an outcry when benches and shrubs were removed from a green space in Kent, while in Eltham, south-east London, police officers insisted that a school, which already had a 2.2 metre-high perimeter fence, spend thousands of pounds installing a new, higher one.

Perhaps the difference is that public opinion is finally moving against outdated design policies dreamed up in the 1980s, which even then went against the grain of expert opinion, and where public opinion goes policy often, but not always, follows. We can but hope.

Anna Minton is the author Big Capital: Who is London for?, published by Penguin. She is a reader in architecture at the University of East London.

The photo is by Oliver Cole via Unsplash.