West side story

Knightsbridge is a popular haunt of the jet set, so the developers of a former Harrods store knew exactly which market to aim for. Penny Jackson reports

The high, arched windows that now frame the chic modern sofas in the new Trevor Square apartments were originally the light source for the chocolate makers who worked here in the days when the building housed Harrods' confectionery-making department.

The high, arched windows that now frame the chic modern sofas in the new Trevor Square apartments were originally the light source for the chocolate makers who worked here in the days when the building housed Harrods' confectionery-making department.

For weeks before Easter, huge, ornate eggs, decorated with precious stones and flowers, were hand-made here for wealthy customers. The women whose painstaking work went into these fabulous creations would surely smile at the thought that 80 years on, it is their factory rather than fancy fondants that carries a social cachet.

Now it costs at least £1.65 million to move into the one-time confectionery factory - prices for the apartments go up to £10 million. But this was never any ordinary factory; it was the rather prestigious sister building of Harrods' main store, just a stone's throw away up Brompton Road. The vast Trevor Square building was designed by the same architect, CW Stephens, who also has Claridges hotel to his credit.

The Harrods Knightsbridge Depository, to give it its proper name, is a grand redbrick and terracotta building that was briefly considered smart enough to become an extension to the store. Instead, developer Crown Dilmun saw that it was destined to live up to its smart address. The building, which supplied Harrods with goods from shoes to silverware, specially blended tea, roasted coffee and literally tons of chocolate, has finally provided the ultimate must-have product: sumptuous homes.

Trevor Square takes its name from Sir John Trevor, who was Master of the Rolls and Speaker of the House of Commons. His estate was developed by his grandson Arthur Trevor Hill in the early 19th century on the site of Powis House, a late 17th-century mansion once occupied by Sir William Blake. In 1913 Harrods demolished homes on the southern side of the square to build the depository.

The commercial activities that began when the repository was finally finished in the early 1920s, after coming to a standstill during the First World War, needed plenty of space. The result are high ceilings and huge living spaces - some reception rooms stretch to 30ft.

Each apartment has a bespoke Poggenpohl kitchen-cum-breakfast room, separated from the reception rooms by sliding glass doors, with white granite or limestone worktops and a range of integrated stainless steel appliances, including the now-compulsory cappuccino maker.

The apartments lack none of the luxury finishes; the master bedroom suite's bathroom boasts white Carrera marble flooring, Hans Grohe and Starck fittings, free-standing bath and a separate double shower cubicle. The family-size penthouse master bathrooms also have double shower cubicles with body jets and a dressing area that leads out to a terrace. All of the homes have audio-visual and alarm wiring already installed - a home entertainment package comes separate, with plasma screens, speakers and control panels in every room.

The first-floor apartments - one a show flat on two floors - enjoy copies of the 1920s arched windows. The £2.75 million show flat has an additional entrance on the ground floor where there is a third bedroom and shower room. The extensive glazing at street level makes it an ideal office area with a study rather than a bedroom.

But it is in the £10million duplex penthouse, over nearly 5,000sq ft on the newly created upper floor, where the painstaking renovation is most evident. The entrance hall has a curved staircase encased in glass and the main L-shaped reception room is 40ft long, with a terrace the size of a small flat at one end and a balcony at the other end. It also has a separate dining room and a second entrance.

In the as-yet unfurnished apartment, the American black walnut doors and architraves with wide oak strip floor form a striking backdrop, although the pleasure of doing it up in this price range will undoubtedly stay with the interior designer. No one, though, can improve on the views and the outside space that virtually surrounds the penthouse has outlooks so different that the rooms almost seem unconnected.

Looking south, you can see Battersea power station and the panorama sweeps across rootops, chimneys and the London skyscape taking in the Albert Hall, church spires and treetops. The master bedroom has walls of glass on three sides offering what can only be a stunning night-time view, and a third bedroom leads on to a large, very private outdoor terrace, which would make a perfect roof garden, secluded as it is by the original brick parapet wall.

At the back of the building, a south-facing, hard-landscaped garden with water feature has been created. Apartments facing this have full-height glazed doors that open on to glass-fronted terraces. As well as the apartments, Trevor Square includes two newly built townhouses adjacent to the main building and two mews houses in Montpellier Mews.

Crown Dilmun have taken on board the nature of the housing market in Knightsbridge and designed the homes at Trevor Square to appeal to international buyers. Period properties with an interesting history tend to be particularly popular with American and Japanese buyers - as long as they include air cooling systems, under-floor heating and, preferably, services fit for a five-star hotel. Trevor Square has this all, plus valet parking, a full concierge service, and other staff by arrangement.

On current trends, the most likely foreign buyer will be Russian. Harrods Estates say there are now more than 40,000 Russians living full or part-time in London many of whom favour high-security properties in central positions. Were any to decamp to Trevor Square it might not be just the underground car park they find useful. The depository and Harrods were once connected by tunnels which ran under Brompton Road. The agents' particulars makes no mention of what happened to them.

Sales agents are Harrods Estates (020-7225 6506) and Knight Frank (020-7590 9911); www.trevorsquarelondon.com