Buy Of The Week: Chelsea

Oh, yes. The minute I walk through the door of my £3.5m Chelsea penthouse, I feel very much at home. The white piano, the Oriental-style gold wall-screens, the silver lobster on the dining room table, the rooftop views over the houses of people poorer than myself - these are me to a T. As for the exhilarating sense of space - 35ft-long sitting room, 28ft-long entrance hall - well, this is what one comes to expect when one has attained , shall we say, a certain level of lifestyle.

Only one problem. The place isn't mine. You see, before parting with a penny, I have asked the estate agents if I can try the place out first. After all, if you can take a £3,500 Skoda for a spin before buying it, then shouldn't the same test-drive facility be made available when you're purchasing a £3.5m penthouse?

Or make that thinking of purchasing. I'm not going to make my final decision until the end of my single-night sleepover, by which time I will have acquired a clearer picture of factors, such as noise levels, neighbour intrusion and general user-friendliness of the flat.

But there is one slight complication, in that No. 35 Benham House is a show home, and it's not entirely clear which bits are show and which bits are home. For example, the appetising-looking loaf of thyme-and-olive bread turns out to be as solid as prehistoric rock. Everyday household items are strangely absent, too: there's no clock, no washing-up liquid and no mugs. The drawers are full, not of tablemats and cutlery, but box after box of ceiling-spotlight bulbs, which gives you some idea of how quickly you'd get through them were you to take the place on. It's also rather eerie living in a place surrounded by framed photographs of the fictional show-family who are meant to live there.

Everyone who lives on this development (King's, in the New Kings Road) gets their television automatically plugged into to every satellite and terrestrial station going, but because the show-family don't exist, they haven't tuned in their impressive TV.So, instead of swigging Champagne in front of my own 4ft-wide plasma screen to watch the football, I find myself at the pub down the road with a pint of cider and a crick in my neck because their TV set's mounted too high up the wall. Ironically, one of the teams playing is Chelsea, whose ground is just a goalkeeper's punt from my penthouse.

Walking back from the game, I am heartened to find that once darkness has fallen, you have to go through a security gate to get in (keeps the riff-raff out). I'm also impressed by the way the concierge asks if there's anything I need doing to help me settle in; most of the porters I know spend their lives shut away in a thick tobacco fug, trying to avoid lifting a finger on the residents' behalf.

As it happens, I do feel there's something missing when I open the front door and re-enter my sixth-floor Shangri-la. And that's people. Let's face it, there's no point having a great, big, showy-off home in the clouds unless you can invite people round to go, "Ooh, what a fantastic place". Also, when you're on your own and wealthy, the mind plays the kind of tricks it wouldn't play if you were on your own and broke. All of a sudden, you start imagining the city's full of psychopaths whose modus operandi is to follow millionaires home and then bludgeon the secrets of their safe combination out of them.

Hardly surprising then, that after a night spent half-listening out for footsteps, I'm in the mood next morning for human company, and head straight down to the private pool and gym. Only to find that my fellow development-dwellers (the King's site has 280 apartments) have all been and gone. "From 6am to 8am is our busiest period," says the attendant (it's now 8.45). "You've got the place pretty much to yourself now."

It's true. Apart from myself, the only people in the pool are a couple of small children having swimming lessons with the resident coach, while their nannies look on. As for mum and dad, they've showered and breakfasted, and will have been at their office desks for the best part of an hour.

Those of them that are in the UK, of course. Posted all over the leisure club are notices urging residents not to leave kit in their lockers while they're away on business, and telling them what appliances they're required to turn off if they're going to be out of the country for more than 21 days.

Where are all the brightly coloured posters advertising jolly social events and barbecues? There aren't any. In fact, the impression you get is very much of an international second- or third-home community, where the sporadic nature of people's presence creates an impersonal atmosphere.

I toy with knocking on front doors and saying hello to the other residents on my landing, but I decide against it because I feel it transgresses a sort of unwritten code of millionaire conduct. Just as you don't want other Brits in your holiday photos when you go somewhere exotic, so, when you've spent millions on a secluded rooftop retreat, you don't want your next-door neighbours popping round and reminding you it's not so secluded after all.

So I end my stay without having spoken to a fellow resident. With one last look at my lost empire, I pull the front door shut and head for the lift. Half an hour later, I'm back in my cramped little suburban home - and glad to be there. I've had my taste of penthouse living, and can now confirm from first-hand experience what everyone always tells you. That it's lonely at the top.

Get the spec

What's for sale: a 13-room, split-level, 6th-floor penthouse at Benham House, the King's Chelsea Development on New Kings Road.

Serious kit: 35ft-long sitting room, 28ft-long hallway, large roof terrace, computer-programmed lighting system, plasma TVs

Other benefits: private pool and gym, concierge

Buy it: £3,495,000 through Aylesford Estate Agents (020 7351 2383).