Urban sprawl has been a problem in the past as London grew outwards, to prevent this growth, the government brought in a 'green belt' around major cities in the UK, which prevented development and kept the city contained
However, there is a shortage of housing and land in London to meet this demand, the number of new homes given planning permission on London's rural fringe has tripled. These homes have been built on the opposite side of the green belt and created commuter towns such as Luton