Suburbia has never had a good reputation. Opposed by both the urban intelligentsia and those who live in the countryside, it is frequently the butt of jokes, epitomised in the oft-repeated BBC comedy The Good Life.

But suburban living has much to recommend it. Well designed suburbs are built at sufficient density to support local services and still allow everybody a bit of space. They are frequently characterised by good schools, and relatively low crime levels. They also offer high levels of accessibility to city centres for those whose jobs require them to work in the central business district.

The first half of the 20th century was a period of significant urban sprawl in Britain. Since the war, however, urban sprawl has been heavily constrained in many places by green belt policies.

Although politicians have claimed that such policies are costless, the evidence suggests otherwise. House prices in heavily constrained cities, notably London, are extremely high by historic and international standards, and in comparison with the cost of building houses. Green belts push up the value of housing land, which in turn means that those who are less well off end up very badly housed.

If social housing professionals are serious about improving housing for their clients, they need to be much more radical in speaking out about the underlying causes of housing poverty. One half of this issue is low incomes – a topic to which I will return in future. But the second half of the issue is high house prices.

There are groups – such as the Campaign to Protect Rural England – that strongly defend Britain’s green belt. Where are the people determined to oppose them, determined to fight in the corner of those who are marginalised, and condemned to poor housing?

There are now around 4 million people on social housing waiting lists in England and Wales. Given that the government has run out of money and is borrowing so much that it will soon run out of willing lenders, and given that it has all sorts of pressing emergency needs, it is not going to build millions of social houses any time soon.

Unless we can dramatically lower the cost of housing, those people on waiting lists are condemned to a lifetime of poor housing. If social housing professionals are not prepared to stand up for these people, who will?

The high road

If we want to support building on some of the green belt, we need arguments that are based on more than just the moral imperative of housing the poor decently.

The CPRE claims that eight out of 10 people oppose building on the green belt. Very few of those eight would be directly affected, and those who are deserve compensation. Those of us who are concerned about poor quality housing need to persuade at least four of those eight that their lives would not be affected in any meaningful sense by building as many as 1 million houses on green belt land across the country. Then we will have a majority.

On one level this sounds like a difficult job. Those enjoying the good life in Surbiton enjoy their proximity to both the centre of London and the surrounding countryside. But if we went back to 1920, before Surbiton was built, we could have had exactly the same discussion about Wimbledon.

At that point Wimbledon was not only close to the centre of London, but also adjoined the countryside. Now the people of Wimbledon have to pass through Surbiton to get to the countryside. Are their lives ruined? Clearly not. Wimbledon is an extremely pleasant and desirable place to live. We can see that in the level of house prices. People like living in Wimbledon, and people would still like living in Surbiton if London was expanded by another mile.

Building another mile of housing around London would, with standard suburban planning densities, create housing for around 1 million people. It would mean that someone leaving London on the A40 or the M11, or on a train to Brighton or Basingstoke, would have to travel through suburbia for an extra minute. No doubt those people would prefer to travel through countryside for that minute, but it is hard to think that one extra minute of suburbia is a high price to pay to see 1 million people properly housed.

Just as Surbiton makes little difference to the people of Wimbledon, so an extra mile of suburbia would make little difference to the people of Surbiton.

Nor is it particularly important whether these extra houses are social homes or market homes. The vast majority of the 5 million people on the waiting list are currently in private rented housing, perhaps sharing with friends or people they do not know that well, or they are living with parents.

If we build more market houses in sufficient quantities then house prices will fall, and private rents will fall with them. This, in and of itself, will help those who are badly housed. Those with too little space will be able to afford somewhere bigger, those who are sharing will more likely to be able to afford a place of their own.

Of course, building more market housing is not a panacea. There will always be a need for social housing. But more housing of any sort is needed, and to achieve that we have to be prepared to take on organisations such as the CPRE, to point out how some of the policies it advocates affect the very poorest people.

Yes, the countryside needs champions. But the badly housed need them too.

Dr Tim Leunig is an academic in the department of economic history at the London School of Economics. He lives in Surbiton