“I go to the same place for my papers, coffee, flowers, and they all know me. “When we began work on our first scheme in Clerkenwell in 1992, an Art-Deco industrial warehouse in Summers Street, we looked at the City of London residential numbers and there were only about 5,000 people living in Clerkenwell,” says John Hitchcox “Now it must be 10 times that. We were instrumental in bringing Clerkenwell along.”Conveniently close to the City, within walking distance of the West End, Clerkenwell was traditionally an area of workshops and factories, site of the meat market at Smithfield, a large mail sorting station, and home to a flourishing Italian community that earned it the name “Little Italy”. Because New River Head is in the right place at the right time; Clerkenwell is currently the place to live.Earlier this year, Vogue identified Clerkenwell as “the nearest thing London has to Manhattan’s SoHo or TriBeCa of 20 years ago”. Walking down its streets now, many of the brass plates by office and workshop doors are for publishers, designers, photographers. It is the spread of residential redevelopments like New River Head that has made this new popularity possible.

Thames Water will retain ownership of it, but will allow residents to use it for entertaining And the neighbours are in keeping with such grandeur. Next door is Sadler’s Wells Theatre, currently also undergoing a radical facelift that will redevelop it into a world-class dance and musical arts centre.The show flats, fitted out with the Shaker-style kitchens, smart bathrooms, and the restored original parquet floors that feature throughout, have only been open for a few weeks, but 25 per cent of the development is under offer. The Oak Room was transferred complete into the current New River Head, built on the site of the ancient supply reservoir. The Oak Room’s dark panels were richly carved by master craftsman Grinling Gibbons; exquisitely delicate fish, birds, crabs and lobsters run riot over the walls. There has been a “water building” on the site since the 17th century, when a 20-mile long canal, the New River, was dug out to connect London’s growing population with two fresh water springs in Hertfordshire. The dark wooden panels of the Revenue Hall where local residents queued to pay their water bills are being restored and reinstalled; a number of the apartments will look out into the hall, which will remain an area of the development held in common. The main marble stairway, with its bronze balustrades, sweeps graciously upwards.

The most expensive apartment will have the old boardroom as its living room, with the orchestra gallery, high white columns and original marble light fittings still in situ under the lofty 30ft ceiling.And hidden deep in the heart of the complex is the Oak Room; dating back 300 years, even before New River Head itself was built. Look upwards and there is the elegant plasterwork, and detailed decorative stone carvings. “When you purpose-build, you build to a minimum standard; but with a conversion like this, you are constrained by the building,” says Hitchcox, who has had to keep in mind that New River Head is Grade II listed, and, at the same time as wrestling with modern fire and safety regulations, has been working under the watchful eye of English Heritage.So today, the main bronze doors open onto an entrance hall whose grey and black Art-Deco marbled floor gleams as proudly as it ever did. The good burghers of the old Metropolitan Water Board did not stint on features that today’s cost-conscious builders could not begin to budget for. They began work on New River Head in 1908, as an imposing proof of the company’s status; it took 12 years to complete. Sadly, such monuments are expensive to maintain; hence the later additions of false ceilings to conserve heat, partitions to make more efficient use of space, Hooverable carpets instead of high- maintenance wood and marble.But now the common parts of New River Head are being restored to their former glory; a glory that will be found in few modern buildings, however exclusive they may be. “We spent the Eighties converting Victorian houses into flats, always on a small scale, so we began looking for buildings with space, volume, light,” he says.

Warehouses can be perfect; but old municipal buildings are equally suited to this kind of new lease of life.Hitchcox is overseeing the division of New River Head into 129 apartments “The building actually falls apart so naturally,” he says. “When it was built, the designers were looking at a good supply of natural light in every room, and they achieved it – the arrangements of corridors, spaces, windows and those two big lightwells mean that as a conversion, it’s very, very simple.” They cost from pounds 115,000 to pounds 575,000, but the high Edwardian ceilings and enormous windows mean that even the smaller ones will feel spacious.There are more advantages, however, than high ceilings. Light and space are his priorities, whatever building he is working on. New River Head stands grandly at the top of wide and tree-lined Rosebery Avenue in Clerkenwell. The building is roughly triangular, with two glass-roofed atria allowing light right into the centre of the building; its brick and stone facades are styled like a French chateau, set in an acre of garden boasting a listed rose garden and fountain.
But according to John Hitchcox, managing director of the Manhattan Loft Corporation, principles that apply to warehouse-loft conversions can be applied to a redundant faux chateau. New River Head, formerly the headquarters of the Thames Water Board languished under this treatment until the company relocated; now it is being brought back to life as a residential development.