If you’ve been reading the news recently, you’ve probably heard the term ‘defensive architecture’ – but what exactly is this and what does it mean for our towns and cities in the future?

Manchester architects (Cheshire) will tell you that defensive architecture is the modification of public spaces and buildings to discourage people from loitering. No doubt you’ve heard of the homeless spikes that have been cropping up in various places around the UK over the last couple of weeks – last month, for example, department store Selfridges installed some of these outside its flagship branch in Manchester, a move that attracted criticism from charities such as Crisis.

And in the summer of last year, 17-inch anti-homeless spikes appeared outside a London apartment block to prevent people from sleeping in the doorways, although these have since been taken down following a petition signed by nearly 130,000 people calling for their removal.

This is perhaps one of the more extreme defensive architecture measures, but other steps include slanting windowsills to prevent people from sitting down, sprinklers that come on randomly even when there’s nothing there to water and benches with armrests that mean it is impossible to fully recline.

Guardian writer Alex Andreou recently took issue with these architectural defences, saying: “It reveals how corporate hygiene has overridden human considerations, especially in retail districts. It is a symptom of the clash of private and public, of necessity and property.”

From an aesthetic point of view, this form of architecture may well deter homeless people from spending time in various parts of any given city, but at the same time the appearance of urban areas is hardly enhanced by their introduction in the first place. They make towns and cities seem unwelcoming and hard, with homeless people conveniently hidden out of sight.

To see more types of defensive architecture on film, visit the Dismal Garden blog of UK artist Nils Norman, where you can find hundreds of photos of the different measures towns and cities are using to keep loiterers at bay. Where do you stand on this type of architecture? Let us know in the comments below.