There's always room at the top

There's never been much kudos attached to prefabricated homes. But a clever company of Swedes is now reviving them and turning redundant rooftop spaces into luxury penthouses

The day after storms swept across the country, half a plastic-wrapped kitchen with units and sink in place was winched up to the top of a London building. It sat overlooking the Royal Albert Hall as the process was repeated until all parts of the structure were in place. A penthouse had arrived, fully formed down to its last light switch.

The day after storms swept across the country, half a plastic-wrapped kitchen with units and sink in place was winched up to the top of a London building. It sat overlooking the Royal Albert Hall as the process was repeated until all parts of the structure were in place. A penthouse had arrived, fully formed down to its last light switch.

Prefabrication, in the minds of many people, is associated with overspill classrooms, not £2m homes, but First Penthouse, the Swedish company geared to transform a rooftop overnight, demonstrates that style and finish can be created in a factory. Their trump card, though, must be that it is achieved with the minimum of disruption.

At Albert Court in Kensington, only the weather last week was likely to disrupt the schedule. Wind reports, on the hour, left nothing to chance as each module was craned up to the roof. Preparation had taken longer than usual because of the clutter of lightwells and chimneys.

"Some residents did need reassuring about noise, and that the ceilings would not collapse. But during the structural work we have non-disturbance regulations and don't use really noisy equipment such as hammer drills," explained Jimmy Pettersson, the company's marketing coordinator.

Everything possible is done in the factory - tiling, shelving, plumbing and electricity - and is tested before leaving. Even the roof slates were sent out to Sweden and added to the new one. In the first show flat that has just been completed, Pettersson points to where the sections join. Rather like vast Lego pieces they are matched up on site. A strip of wooden flooring and a small panel of the wide living-room window were slotted in to complete the picture. In the rest of the penthouse, wardrobes, desks, showers and units arrived fixed and functional.

How does this go down with the British market? Jimmy Pettersson recognises that it is not always easy to persuade buyers who are more comfortable with bricks and mortar that timber is as durable. The first two apartments at Albert Court were sold to overseas buyers off drawings, a process about which UK buyers are still lukewarm. At Sotheby's, the selling agents, Charlie Smith says most people want to make minor adjustments to a show flat rather than start with a blank sheet.

The first prefab penthouses were built by the company in St John's Wood, north London, in the early 1990s and the final two of the seven apartments, sold off-plan to English and Swedish purchasers, have just been completed. At Albert Court, Pettersson zooms in on London's rooftops via his computer. "We have 700 potential sites. It could mean going into a joint venture with the freeholder or acting as a contractor." He calculates that the minimum turn-key costs for 350sq ft would be £100,000.

One of the first people to spot the potential of a system that promises a finished extension with the minimum of fuss, was Carol Thatcher, daughter of the former prime minister. She wanted a small studio on her roof terrace at Bankside Lofts close to the Tate Modern on London's fashionable South Bank.

Annika Ollsson, design manager of First Penthouse, says she sat down with Ms Thatcher and drew up in detail all her requirements, from bookshelves to storage cubes on wheels for hiding bedding during the day. The extension, which was approved by the building's architect, Piers Gough, is approximately 4m x 7m and tucks in a kitchenette and shower.

Carol Thatcher was initially drawn to the idea after she had endured the exhausting business of fitting out her loft. Annika Ollsson says the original cost of about £50,000 was higher after the furniture and fittings were added. "It is up to the owner to decide how they can cut costs. They can do some of the fitting out themselves if they wish to save money. If that is not a concern, we will ship all the components they have chosen out to Sweden and assemble them there."

It takes about five months for a project to go from drawing stage to completion. Although the roof must be prepared, scaffolding and workmen are only in evidence for a short time. There can be no last-minute requests from the clients, not least because the men installing the structures are Swedish. They follow their handiwork out from the factory and finish it to their standards.

"We have been asked to do all sorts of extensions, at ground level and on the top of garages. But we are specialists in developing roof spaces and, for now anyway, we will stay with that," says Jimmy Pettersson. "There are many perfect roofs in New York and Paris as well."

* Penthouses at Albert Court from £2,450,000 through Sotheby's International Realty: 020-7598 1600; First Penthouse: 020-7584 9894