VIEWED from the roof of the council offices, Stevenage, a town of some 85,000 people around 30 miles from London, is not an attractive place. To the east, a shopping precinct—three low-rise grey blocks around a clock tower—squats in front of brown concrete tower blocks. To the west, shed-like buildings—a bowling alley, a leisure centre and a sort of strip-mall—loom over acres of car parks and roads. Stevenage was the first new town planned by the post-war Labour government in 1946. It was not all that popular even when it was built—residents of the old town renamed it “Silkingrad” mocking the grandiose ambition of Lewis Silkin, the minister responsible. Yet today it is a remarkably successful place. Its residents earn more than the national average; the local employment rate, at 81%, is higher than almost anywhere else in Britain. Businesses such as GlaxoSmithKline, a pharmaceuticals giant, flock to its industrial parks, and residents of the smaller towns nearby drive to its shops.

The legacy of Britain’s new towns overall is mixed. There are 22 of them across the country, as well as several “expanded towns”. Together, they are home to around 2m people. Built between the 1940s and 1960s, they were the product of the post-war centralised state, which aimed to demolish Britain’s bombed-out Victorian slums and build new rationally planned, semi-rural settlements. New towns offered a modernist future—an “essay in civilisation”, as Lord Reith, who helped design the plans, put it. Certain features unite the breed. They are mainly near motorways and railway lines and between 20 and 40 miles from a big city. Brutalist architecture, with concrete underpasses and walkways, is common. Low population densities abound, with parkland separating roads and industry from housing. Most new towns have efficient road networks, with ring roads and multiple roundabouts.

Housing however divides them. Mark Clapson, a historian at the University of Westminster, recalls that in the first wave of new towns such as Harlow and Stevenage built in the 1940s and 1950s, planners only allowed for council rented housing, which turned them into working-class enclaves. In Milton Keynes, which was built later, the suburban semi-detached houses were mostly sold to middle-class escapees from London. “Our nice new town where the curtains are drawn,” mocked Paul Weller, of the Style Council, in 1985. Another band of the era gloomily dubbed themselves “The Newtown Neurotics”.

Even now, success is unevenly spread between them. More northern ones such as Redditch and Corby, still rely heavily on manufacturing for employment. Those near London lean more on commuting and the capital’s outgrowths. In Stevenage the growth of the service economy has made up for the loss of British Aerospace jobs; blue-chip technology firms have set up in Bracknell. Milton Keynes had the fastest-growing economy outside London between 1997 and 2011. Harlow has done less well, but its MP, Robert Halfon, points to impressive business start-up figures.

New towns succeed because they offer something that is scarce in London: cheap land. In Harlow the Newhall extension, a bright splurge of plush family homes, sits near the M11 motorway on greenfield land. In Stevenage the council is trying to push through plans to build up to 15,000 new homes on its fringe. In Milton Keynes the grid layout leaves plenty of land with infrastructure ready for developers.

That attracts politicians, who spy a solution to Britain’s acute housing shortage. When Labour was in power, Gordon Brown planned several “eco-towns” to be spread mostly around the south east. David Cameron and Nick Clegg have both suggested building new “garden cities” to take the pressure off London. Building new towns—and extending existing ones—would help meet housing demand without picking fights with the residents of every nimbyish town and village.

Yet the lesson of the new towns is that being linked into a bigger city fosters growth. Their success owes much to the other part of 1940s planning—the tight green belts which still surround big cities and squeeze investment farther out. The notion that they would be self-contained economies has largely failed. Perhaps it would have been better to have built more in the green belt after all. Next to tired Stevenage, those once-derided inter-war suburbs now look quite appealing.