"Delete! Delete!" protests Rosalyn. "I never say that! I was very diplomatic as I didn't know John that well, and he'd already decided to buy the place. But, in the five years that I've consulted people about feng shui, there have been two no-nos, and this was one of them. Feng shui works on a square or rectangular principle - John had a triangular building in a triangular plot, so he'd missed half the numbers on the plot, and half on the apartment. Plus, inside, there was a courtyard with the sewage pipes of the whole block running right down his chi. I said, 'you can make money here, but you'll be single, you'll be unhappy and you'll be less well than you could be.' "
Two and a half years on, John and Rosalyn are a couple, by all appearances in the best of health, and gales of laughter punctuate their conversation. Not surprisingly, they don't live in the triangular apartment but in a light and airy open-plan house nearby, discreetly arranged along feng-shui principles. "I carried on designing the flat," says John, who started in developing in 1981, with no architectural training, "as we weren't together at that stage, but it niggled me. I'm superstitious - not hugely - but it got me going. Quite by coincidence, somebody told me a whole house nearby, that had been converted into five flats, was coming up for sale and that I should have a look at it. I went round and bought the lot in half an hour."
For a man who has made his money converting commercial buildings into ultra-urban residential lofts, the idea of buying flats to convert most of them back into a single house in leafy west London might seem strangely against the grain. Then John mentions his two children, Pia (four) and Henry (seven), who divide their time between a country life with his former wife, Anna, and him. "The big thing for me was that I was always going to be a single parent in London, with kids at the weekend. Generally, in a loft you don't have much external space and kids like to run around. They go out into the [smart communal] garden here and make half a dozen friends." He adds, mock-ruefully, "when I run out, nobody comes and plays with me!"
John hasn't altogether abandoned his commitment to the light and space that are so essential to loft-living; the central part of the high-ceilinged Victorian house's first floor has been cut out to create a giant, two- storey lightwell. "We made an open staircase so you could enjoy travelling through the space and seeing it from different aspects. It takes out an element of cosiness, but I like the feeling of expanse you get in return." From the top of the stairs, where the bedrooms are tucked away, you can see right down to the kitchen- and dining-area which forms the heart of the house. The result is modern, without ignoring the original proportions of the house. At the back of the house, two storey-high sash windows marry the Victorian exterior and John's love of light.
Trying to work out which bell to press at the front door is a confusing business, as there is a rash of Hitchcoxes listed (more than there are occupants, in fact, but this makes up the correct feng-shui number for Rosalyn). When he bought the house, John was living a bachelor existence so didn't need the whole space. "It worked out really conveniently: my brother David was just starting out as a film director, so he took the top flat, and my sister took the one beneath. It's great for the kids to have their uncle and aunt nearby, as it created a family environment when they were going through that difficult period of their parents separating." They all share the same front door, but the flats are separate from the main house.
This Waltons-like set-up stretches to the business as well. The late Hitchcox senior, Brian, was an architect, as are John's sister upstairs, Min, and her boyfriend, Mark Davison, who do much of their work for the Manhattan Loft Corporation, which John founded with Harry Handelsman in 1991. Piers Gough was the architect on its first project, Summers Street, in Clerkenwell, and has been working with the MLC ever since. He's just done its latest swanky project, a former cocoa warehouse at Bankside, south London. "He completely understood the concept of urban development with flexibility of space," says John. "We were acting as facilitators, taking nice buildings and giving people the freedom to define their own spaces. Our lofts were presented as ready-primed blank canvases.
"I remember my father working on projects like ours 25 years ago," he continues. "People were looking at contemporary design, but it was more from an architectural angle. What we've done is to take the concept out into the market-place." Another key to the MLC's success is to spot areas ripe for development: Clerkenwell, Bankside, Old Street, St Pancras - all near the Square Mile but run-down and considered beyond the pale.
About 50 per cent of the MLC's apartments are now fitted out, to save people the bother of using their own imagination. But when it came to his own house things were very different. "Last time this place was touched was 100 years ago," says John, "and so you try to get the wallpaper off and the plaster comes away, and when you take off the plaster you find the wood is rotten. With one of our lofts, you know you won't have to deal with that sort of thing."
Even Rosalyn is now involved in the family business, working on 12,000 square feet of former High Anglican parish church in Petersham, Surrey. "I've sort of semi taken off my feng-shui hat," she says, to return to design, the profession in which she started her working life. She's also been a developer before, and like John, comes from a family of five children. Here the comparison ends: whereas he and his siblings went to a Rudolf Steiner school, and led what Rosalyn describes as "an Enid Blyton existence", Rosalyn's mother died when she was six and her father, a doctor, "lifted anchor and travelled the world", taking his children with him. "I went to 18 schools and lived in about 30 homes," she says. "I suppose it drew me naturally to familiarising myself with new buildings or ships' cabins." About 12 years ago, she started reading about feng shui. "In a very short time I was goose-bumping," she remembers. "It was so much how I'd been working. I could get to a site and home in on exactly the kind of space that felt good to be in, but I didn't know there was a name for it. Feng shui is 85 per cent good old-fashioned ergonomics: it is practical, it really does work, it makes good design great." She is now writing a book to convince others of its benefits.
Chinese practitioners might feel there is rather more to it than that, but Rosalyn pares down the rules to suit contemporary clients brought up in Western cultures. She avoids "esoteric" practices (as she describes them), such as putting a piece of burnt tangerine in your pocket to bring happiness to your day, though she draws a fine line between superstition and practicality: when I left the loo-seat cover up, she rushed to close it as we passed the bathroom. "You should never energise a toilet area," she says, "because then you are expanding the negative energy in it. What you can do is put the lid down to prevent it." Having green plants in a bathroom will also, apparently, help counteract such negativity. Like the dietary laws of Judaism and Islam, such rules would have made more sense in the days of rudimentary hygiene, though even with modern sewers, a fern and a tidily closed loo do make the room more attractive.
Going round the house with the couple is a lesson in gender re-affirmation. Although it was designed to John's masculine preferences (open-plan, white-walled, matt-black gadgets and a snooker table downstairs), Rosalyn has sneaked in her feng-shui "balances" almost without his noticing. "First I've heard of it!" was a frequent remark, as Rosalyn explained various details - the square green wall- hanging representing the element of wood behind the bed, which faces south- east in the correct alignment, or the long, frosted-glass doors on the walk-in wardrobes to prevent the mirrors on the end walls reflecting the bed, and causing unquiet sleep. On John's bedside table there is a telephone, alarm clock and television remote control (all in black); on Rosalyn's painted Indian table, an assortment of cultural odds and ends that perhaps reflects the years she spent in California in the Eighties - a Hebrew blessing book, pictures of a cabbalistic rabbi and the Indian guru Sai Baba ("one of my dearest girlfriends follows him, and she is so pure of heart that he has to be someone special"), a couple of stones, two little statues, a crystal - each has a spiritual significance to her.
Not all of Rosalyn's "balances" were introduced so subtly. Her insistence that the cooker should face south-east (to optimise the energy element in the food prepared on it) caused a squabble, but that was her only major demand. The bold, bright colours of the furniture are, in feng-shui terms, "hot" colours, to melt the "metal" element of the white-painted walls; and in design terms, modern and perfectly suited to the open-plan space, preventing it from looking cold and cavernous. But, apart from the odd wind-chime in strange places (such as the bend in the stairs), it would be difficult for an untutored eye to spot the influence of feng shui.
The place looks pretty together, happily marrying the two approaches, but John insists it is not yet finished. "I think it's a Hitchcox tradition," he says. "You never think a house is quite there and probably the day we finish it will be the day we move out." The garden is still to be worked on, and whether Rosalyn gets to keep her three stone lions to guard the gate has yet to be debated. I suspect they will remain, tucked into a corner, quietly doing their job. !