Relics from another age offer scope for the sort of conversions that change unfashionable addresses into the haunts of film stars. Penny Jackson reports
A converted stable block and a church tower have more than their 18th-century origins in common. They are both in south London and carry a price tag of pounds 1m. On the edge of Clapham Common, Robin and Caroline Totterman have created an oasis in Nightingale Lane. They have transformed the derelict building tucked away between flats, which briefly saw life as a restaurant, into a 3,200 sqft home that combines all the appeal of a spacious loft with details of the old stables. Both refurbishments were a labour of love, taken on by enthusiasts who felt instinctively the potential of the buildings. Architects' ideas often clashed with their own and so they drew their own designs, keeping professional input to a minimum. They learnt the hard way and at times thought their ambitions had got the better of them.

When the Tottermans finally moved in, by now with a small baby, they were suddenly assaulted with horrendous smells. "We thought it was a gas leak, then the drains but no one could find anything. We also had problems with the electrics. In the end we took up the new floor and found that the open drains from the stables were letting in the smell from the sewers and rats were eating through the wires," recalls Robin. "We had to seal it and lay the whole of the ground floor again."

Since it is open plan and about 50 ft in length, this was no small task. But despite this setback the house had begun to take shape. "We would sit and debate all the details with the builder as we went along," he says. "We became our own developers." It took a year for the purchase of the stables to be negotiated. They bought during the property doldrums and from an asking price of pounds 500,000 they talked their way down to about a third of that.

"We walked past it every day and from the moment we walked in we knew it was just what we wanted," says Caroline. She is no stranger to design. Her background is in the theatre, as is that of her family - Oliver Reed, the actor, is her uncle - and she designed many of the visual merchandising campaigns for In-Specs, the trendy eyewear company founded by Robin. "We were clear we wanted a lot of space," they both say. In the courtyard outside the kitchen the original stable flooring has been restored. A spiral staircase leads up to a roof garden off a bedroom and a sauna sits in what was an outside passageway. Now it is on the market with a pounds 1m price tag. "It was a labour of love," says Caroline. "We never imagined five years ago we would be selling it at this price."

Edward Caudwell, for the selling agents Aylesford, is seeing people moving south of the river who would never have dreamt of it a few years ago. "A million pounds is a psychological barrier, but when people realise they would be paying more like pounds 3m in Chelsea, it isn't difficult to lure them out. I even blindfolded one buyer and drove him to Battersea. When he saw the house, he bought it." Even so, buyers will not be pushed into paying silly prices, he says.

In areas where houses are clearly in a different category from their neighbours, pricing can be difficult. Heather Pontifex, of FPDsavills, says that now precedents have been set in Wandsworth and Clapham comparisons can be made, but in the case of Gypsy Tower, the spectacular church-tower conversion, it is much harder.

Every morning, Michael Rubino noted the burnt-out church in Gypsy Hill as he drove past on his way to work. Three and a half years later the vision that gripped him when he first stopped for a look has become the reality that drew Madonna four miles south of fashionable London to inspect. It is on the market at pounds 1.2m.

It would be unique in any setting. Rubino, an interior designer, and his business partner Michael Edwards-Hammond bought the church from a frankly incredulous diocese for pounds 13,000. "Nobody wanted it," says Edwards- Hammond. "English Heritage, who were dealing with it, thought we were mad."

Rubino, who had always wanted to live in a church, took control from day one and set about the task with a passion. "If I had known what it would involve I would never have started," he admits. As it is, he has created a home with all the features of a modern development - closed- circuit TV, a lift, sprinklers in every room - the romance of a roof- top garden overlooking London, and where taking a bath means looking up through a glass roof to the summit of the tower. He hunted down wall lights in Italy, appropriate for the enormously thick walls.

Edwards-Hammond began to watch the finances nervously as expert restorers repaired the charred timber and stone and whatever could be salvaged from the arsonist's vandalism. The only floor in existence was in the belfry and that was "two feet thick in pigeon droppings". Now it is enclosed by 44 windows. Below, in the clock room, the exposed workings of the clock have been repaired by the original makers. "We spent pounds 600,000 on it in the end," says Edwards-Hammond. Madonna is not the only celebrity to show an interest. "When I was in America I showed the pictures to Cher over lunch. She loved the place. Can you imagine her living there? No one would expect to find her drinking in a wine bar in Gypsy Hill."

You wouldn't have to blindfold anyone to buy south of the Thames if Cher exchanged a Malibu address for SE19.

The agents for Nightingale Lane are Aylesford (0171-351 2383) and Douglas & Gordon (0171-924 2000); for Gypsy Tower, FPDsavills (0181-877 1222).