This dream of getting the best of both worlds has captivated London's middle class and the housing industry that serves it for well over a century. All the suburbs such as Richmond, Highbury and Lewisham that sprang up towards the end of the last century, as well as the Finchleys and East Sheens of the Twenties and Thirties, were attempts - often brilliantly successful - to satisfy the appetite for this urban/ rural hybrid. And it remains the driving ambition of most young metropolitan couples today. A flat is all right when you are still single or childless, but as soon as sprog comes along, you need somewhere for him or her to toddle. The house and garden idea remains potent.
But as London-style urban living comes under pressures of every sort, from crime and schooling to the commuting headache, a growing number of couples with children are boldly going in the opposite direction: inwards. They are contemplating making a most un-English sacrifice: doing without a garden. It is hard to say how many people are involved, but their number is growing and their significance lies in the fact that they are reversing a long-standing trend. In exchange, they get to enjoy the urban buzz that the suburbs so plainly lack, to live within walking distance of the city's great parks, and to save time wasted on travelling. But they also discover that there are other, less widely appreciated benefits to living close to the centre of town. As you approach the zones that remain the purlieu of the rich, burglaries and street crime dwindle. And even the problem of getting sprog into a good-ish primary school - for many parents the most nerve-wracking challenge of living in the inner suburbs - may be solved with surprising ease, because the good schools are simply less under siege.
It was in the Eighties that yuppies began discovering the joys of living in the city's heart, in modern developments such as the high-rise concrete flats of the Barbican, within the City. The redevelopment of Docklands for housing, which in 1984 helped to halt more than 40 years of continuous decline in London's population, also re-acquainted young people with the notion of living in the sorts of districts that earlier generations would have rejected as too grimy or industrial.
"London had been the area of greatest population loss," says John Hollis, a demographer at the London Research Centre, "but it became an area of net inward migration due to Docklands. People used to come in as young singles, then move out to find more space. But in the past 10 years London has been able to hang on to most people. More and more people ar not moving out."
The redevelopment of Docklands is approaching maturity, but elsewhere in the city the idea is beginning to catch on. Many of Docklands' most popular residential buildings are converted warehouses. In 1992, a development in the district of Clerkenwell, the area north of Fleet Street formerly known as Little Italy, full of tightly winding lanes, showed that the formula could succeed elsewhere. A firm called Manhattan Lofts converted a redundant Art Deco print works in Summers Street into shell apartments, and sold 80 per cent off plan, before the development got under way.
Such conversions have multiplied: another improbable area where buyers can't get enough of them is Bermondsey, south of Tower Bridge, which is also extremely convenient for central London. But for young couples and families on a budget, the taint of the yuppie infects many such conversions: often they seem seriously overpriced, considering how much work needs to be done after purchase.
But those determined to find a place in the heart of town are not easily put off. A new and previously unexpected source of homes is the redundant Fifties or Sixties office block, a number of which have already been converted. Some 25 such schemes are under way, says Geoff Marsh of London Property Research, and about 200 disused blocks might be suitable for conversion into housing or hotels.
If the idea of living in an old office block seems unattractive, consider the pluses: lifts, views, big picture windows, parking, sometimes air- conditioning. A prominent documentary photographer and his partner have just finished converting the top floor of an office block off City Road, just north of the City, into a family home, and have turned the large flat roof into a garden. The city's nooks and crannies yield extraordinary finds to those who persevere, such as the formerly light industrial mews in Bloomsbury where Cany Ash and Robert Sakula have built a delightful small house for themselves and their four children.
Moving inwards is not the exclusive prerogative of those who can afford mortgages. The Oxo Tower, a former factory near the South Bank arts complex, has been converted into housing association flats with a Harvey Nichols restaurant on the top, while the former offices of Rupert Murdoch's defunct Today newspaper in Vauxhall Bridge Road, just south of the Thames, have recently been transformed into affordable housing by Peabody Trust and Notting Hill Home Ownership. Notable London landmarks such as the Shell Building and County Hall on the South Bank are also in the early stages of being converted into housing.
What is happening in London is a major re-ordering of people's priorities and expectations for their homes. For years, young couples craving the inevitable house and garden have moved into areas such as Stoke Newington or Crouch End, inner northern suburbs that seemed to combine the rural and the urban in that unique London way. But many discover in fact that they get the worst of both worlds: the crime of the city without the metropolitan buzz, ersatz rurality without any real peace and quiet - all that, and an unseemly scramble for the one good school. By moving to the centre, more and more are kissing that particular dream goodbye, and embracing one that has more in common with the allure of Paris or Rome or Manhattan.
London and Continental Railways, owner of St Pancras Chambers, has just announced its plan to hold an architectural idea competition to try and discover a future use for Gilbert Scott's neo-Gothic extravaganza. But it's not as tricky a problem as they seem to believe: they are sitting on London's answer to New York's Dakota Building.
Cany Ash and Robert Sakul are both architects in their thirties. They set up home together in Bloomsbury in cental London in 1984, moving from Wapping and Islington respectively. They have three children under nine.Their home is an open-plan, converted, light industrial mews building on two floors,with three bedrooms and a roof garden.
"The centre's a brilliant place to live, because we're exactly half-way between the West End and the City," says Robert. "We work around the corner, so we don't commute, and things like rail and tube strikes just wash over us. London is a wonderful city, but the worst thing about it is travelling in it; if you don't have to travel in it, however, it's ideal.
"I suppose if we sold this house we could probably buy a much bigger house in the suburbs, so in that sense, living in the centre is probably more expensive than living out. But on the other hand, we save on fares, because we cycle everywhere. We do have a car, but it only gets used at weekends. But our moving here wasn't really a financial issue for us, because we bought this place for pounds 30,000 and did it up. We also rent car parking spaces on our property to some lawyers who work nearby, so that also helps.
"What we love about living in this particular part of London is that you can still hear the wind, and the birds singing - it's very, very peaceful."
" We spend a lot of time in a park near here called Coram's Field," says Cany, "which I suppose is a bit special, because you can only go in there if you have children. They've got goats, sheep, chickens and ducks, which makes it seem quite rural, and when it gets a bit claustrophobic in here, that's where we head to let off steam. The only thing we want now is a sort of magic carpet that takes the children there without them having to cross any roads, so they could go by themselves."
"As for finding schools for the children," Robert continues, "we haven't quite got there yet - they're aged eight, four and three. But there's a nursery - once part of the Thomas Coram Foundation, originally a foundling hospital set up in the 18th century, but now funded by Camden - that takes babies from the age of three months. Our two younger ones go there. The staff are fantastic, and it runs from eight in the morning until six at night, every day of the year except for two weeks in the summer, a week at Christmas and a few days at Easter. But it's primary schooling that's more of an issue: we didn't actually get a place for our eldest around here, as they'd underprovided for her year. We ended up sending her to the Lycee in South Kensington - a French state school run for the children of French diplomats and business people. It's fee-paying, but subsidised by the French government. We haven't made a decision about what to do later on yet, but we'd be very loath to move away from here."
Cany insists that there are no real practical problems. "Shopping tends to be done in passing, but when we have to stock up on things, we just go off to the supermarket - there are lots of them around here, and there are some nice street markets, too. We get rubbish collected three times a week, probably because this area is a mix of business and residential buildings, and there isn't a noticeable amount of litter in the streets. Although there's lots of traffic around in the week, there's barely any at all at weekends. But there is a lot of pollution round here - it can be quite choking, especially in the summer - and we've heard that Russell Square, which is just half a mile away, is one of the most polluted spots in the country.
"It's not just a matter of convenience living right in the centre: it's the resources that are around that count. When there's a park festival or exhibition we can just go along, without it being an expedition. Indeed, the best moments to be had living here are when you just go out without a plan: you might go to Soho and sit in a cafe, then wander on a bit to Regent's Park, and end up dropping in on friends. You have a more spontaneous social pattern than you'd have in the suburbs, and meeting other families at Coram's Field is really like sharing a big garden with people."
"Generally, we don't see the hurly-burly of living in the centre of London as so much of a problem as a resource," Robert says. "The area is made up of all classes and all nationalities, which provides a great environment for the children to grow up in: the suburbs feel like a ghetto by comparison. When we go and see friends who live in idyllic little villages in Berkshire, one of the great topics of conversation is 'what the neighbours are doing', but we live on top of about n million people - people who play house music late, that kind of thing - and it's not a problem. People hang out in the street, and it makes for a good atmosphere.
"I suppose the worst thing that could happen would be getting broken into, but it just hasn't happened. We feel very secure here, though that's not to say that we won't ever get broken into. But we'd guess that the crime rate around here is no greater than it is, say, in Harrow-on-the- Hill, or Guildford. In fact, the only real reason there is for us to move from here is that we're getting too big for this house, but we really want to stay. We can maybe create a couple more bedrooms, but if things do get difficult as the children get older, we would just look for a bigger house round here."