Mary Dejevsky: It's time to grab back our gardens

Gardens are not brown-field sites. They are an integral part of the suburban landscape; they are what makes it desirable and family-friendly

Ten years ago I was living in Washington DC and observing a truly distressing phenomenon. Established houses in the nearest city suburbs were being extended or replaced, up to the very edge of the plot. The older clapboard and brick houses which had sat neatly on their lots, with a deck and gardens front and back, were swelling every which way into ill-proportioned monsters. It was only when the conservationist outcry could no longer be ignored that the authorities finally decreed a – modest – minimum space between the border of an existing plot and new building.

By then, though, regulation-lite had done its worst. In the five years we were in Washington, not only was much of the closest countryside, in Maryland, despoiled by a rash of "McMansions", but my favourite inner suburb, a bucolic and rather Russian-looking area known as Palisades, above the Potomac river, had shed much of its charm, to resemble just another congested estate.

On returning to the UK, alas, we found the self-same phenomenon well in train, with a very British twist. Not only had the front garden become, as though by decree, hard-standing for the car(s), but the treasured back garden was under threat. All or part of the green space that had helped sell the house to successive owners was being sold to developers, and the householders – how could you blame them? – were cashing in their gains.

The mystery to me was not why they were selling – that was brutally obvious – but why such sales, which progressively transformed the character of a neighbourhood, had become such seemingly routine transactions. Was it not extraordinary that the suburban house and garden, for so long the English family's dream, was being so casually sacrificed to a far denser form of urban development? And that it was entirely legal.

Severe complications faced householders who resisted. Either they became the stand-outs on the block, ostracised by their neighbours for blocking their fast track to pension security, or they became embroiled in time-consuming agitation to demonstrate, by dint of scouring the plans and taking photographs, that the planned development would obscure the light (one of the few reasons why planning permission could be refused).

I had hoped that the simultaneous trend, at least in London, for houses divided into flats to be converted back into family homes, would slow the disappearance of back gardens. But no; developers only struck out into leafier and leafier suburbs, with bigger and bigger gardens. With school playing fields no longer inviolate, private green space was now vanishing in the same silent and apparently uncontentious way.

So it was with some satisfaction that I learnt of the new government's plan to give councils new powers to stop the development of back gardens. In fact, it has been a good week for green space, what with Prince William championing the cause of school playing fields. But the builders-over seem intent on going down fighting. Anyone who heard the ding-dong between Zac Goldsmith, the new Conservative MP for Richmond Park, and the former deputy prime minister, John Prescott, on yesterday's BBC Today programme will have a foretaste of the battle to come.

Time and again, Prescott put himself forward as the advocate of the disadvantaged, insisting that suburban gardens had to be built on, if the acute shortage of affordable homes was to be addressed. Goldsmith disagreed. Manners, vocabulary and accents all served to give this exchange a distinct edge of good old-fashioned class warfare: Zac, the old (expelled) Etonian squillionaire, defending the ancestral rights of the squirearchy to preserve not only their own, but next-door's, back garden, against proletarian Prezza's concern for the impoverished man, woman and child, begging in vain for a tiny slice of land at the rich man's remote-controlled front gate.

As a dedicated flat-dweller, blissfully content to be free of garden chores, I have no special interest to defend. Nor am I unaware that there is an acute shortage of housing in the south-east, as in desirable rural areas – at least housing that anyone on an average salary can afford. But I have to say that my sympathies are with the Government here, and the proposal of the Communities minister that back gardens should be reclassified as "green-field", rather than "brown-field", for planning purposes. This would would make it much harder for developers or anyone else to build on them.

The real question – scandal, anyone? – is why back gardens were ever classed as brown-field sites at all. I have heard it said that home-owners would otherwise have found it nigh impossible to build the conservatories, gazebos and garden offices that have become the totems of suburban one-upmanship. But there is quite a difference between even the most elaborate garden office and a brand new house or block of flats. Prescott's argument that brown-field classification of gardens has released more land for housing seems more than answered by Goldsmith's point that, given the choice, developers prefer gardens to industrial brown-field sites, because they require less preparation. Of course they would.

The truth is that developers should never have been given that choice. Gardens are not brown-field sites. They are an integral part of the suburban landscape; they are what makes it desirable and family-friendly; they allow people space to breathe, provide children with safe spaces to play and give teenagers hot-weather options other than opening water hydrants in the street.

Affordable family housing is in short supply, but the way to start remedying that is not by concreting over gardens, but by bringing unused housing into use, developing real brown-field sites and removing the tax incentives for investing in tiny flats few want to live in long term. The housing market in this country has been skewed by over-generous credit, perverse incentives for building and owning, and a failure to compensate for the loss of social housing from "the right to buy". If allowed to continue, the "garden grab" of recent years would only reduce the supply of family homes further. That is not a class-based or elitist conclusion, it is elementary common sense.