Interiors: Reach for the sky

Forget about buying land, there is a better way to build the ultimate central London home - find yourself a spare rooftop. Sarah Gaventa looks in on a pioneering Modernist masterpiece, on high

SOMEWHERE over the rooftops of Marylebone, perched on a fine red- brick Edwardian mansion block, sits a relic of Seventies architecture and a testament to an age of more permissive planning laws. Tucked in behind the block's decorative skyline, is a Miesian penthouse, constructed of aluminium and glass, which was designed in 1973 by Nicholas Hills, an architect who previously occupied a flat in the mansion block. Hills wandered up to the roof one day, and was stunned by the view and the 3,000 square feet of potential, and promptly bought it as a site for an unconventional family home.

He designed what he calls "a development of a single room house" based on an L-shaped plan with its back along the outside wall of the building and its front of glass doors opening on to the garden which shares the roof with Hills's glass box.

Flexibility was a major criteria, the main space was designed in modular bays each 12ft by 8ft with independent light switches and power points. The plan being that partitions could be added to divide the bays into separate rooms if desired. Tucked into the L lies a double galley-style kitchen.

Apart from the main open-plan space, small bedroom cabins are incorporated into the outside wall - the most spectacular being a circular room built into an existing turret, complete with circular bed and tented ceiling.

On entering the flat, the ubiquitous brown diagonals which stripe accross the floors, tiles, blinds, cushions and tablecloths, make a striking, even disorientating, series of planes. Combined with the reflective qualities of the acres of glass and aluminium, it creates an illusion of further rooms and corners and it not uncommon for guests, after only limited alcohol intake, to completely lose their sense of direction. Hills now confesses, "I was completely nutty about using diagonal patterns at the time. It gives a room movement, and I designed six or seven versions for various projects. Most modernists are terrified of patterns but I loved them."

In 1976 the Architectural Review featured the house in a photo spread on interior design. They described rather quaintly, the contrast between the living space and the bedroom cabins "these are reached through kasbah-like holes in the walls which give spots of aesthetic warmth to a scheme which, overall, is deliberately cool." Cool! Well, certainly in the Jason King sense of the word, but then this was written before ultra cool "Minimalism" was invented, a term which would have conjured up recollections of rationing rather than design. Unlike the dour Minimalism of today, which claims to be concerned with "space" but in reality presents little more than a vacuum, this house has a distinctive, dominant personality. Hills sees the house as "an exercise in International Modernism, but slightly softened and warmed up". The interior, with its use of bold coloured patterns, was not only the height of fashion, but fun, and it still is. Little has changed in the house since the pictures were taken for Architectural Review, apart from the occupants. Nicholas Hills decamped to Norfolk, and the house has passed on to his son Adam, who recently moved back to his childhood home with his partner Maria Speake. Both studied at the prestigious Mackintosh School of Architecture in Glasgow and run an architectural reclamation and design business, Retrouvius, from the flat.

As a family home Adam felt it had some advantages "being so open plan there was no privacy or quiet space, and the bedroom cabins were like being aboard ship, you had to watch bumping your head. But, as children we didn't realise how lucky we were. Living here as an adult is more liberating and I've now become more appreciative of the design."

Maria, however, loathed moving into a home that was in such a time warp, albeit from a period currently undergoing a revival. "But now I love it," she says, "particularly Nicholas's genius in exploiting the potential of the roof."

Now a quarter of a century old, the diagonal carpets and fabric which were made specially to Hills's design are a little worn, and the aluminium columns are battered. While Adam and Maria's first reaction was to rip out the stripes, after living with them for a while, they are now content to respect the original concept of the space, and updating it by integrating contemporary and eclectic elements. Adam previously dealt primarily in Victorian architectural salvage but, being surrounded by post-war design classics, such as the white leather armchair by Joe Columbo and furniture by Charles Eames and Giacario Piretti, his taste has turned towards dealing in Sixties and Seventies design. Maria felt that the couple had a clear choice: "We could have either treated the flat as a listed building, or given it the opportunity for new life."

Visitors, they found, often react adversely to the Seventies look. "They all dislike the diagonals, but love the space, the view and, of course," and adds Adam, "everyone wants to have sex in the circular bedroom."

The Austin Powers look has been softened by the recent addition of an Ave Maria wall sconce (a love token) and architectural oddments, including a plaster figure of Sir Thomas More nervously clasping his hands as he stares at the carpet.

There is a downside, I'm told, to living in a groovy penthouse in central London as it is "hot and steamy in summer and like Scotland in winter". The house was built in an age when energy was cheap (pre-oil crisis); and, on the tight budget, insulation was deemed an extravagance.

Apart from having to wear layers of thermals when the temperature drops, the flat also makes a perfect live/work space. The studio has been converted into an office to display contemporary work by textiles designers Timorous Beasties and French glass designer Guillaume Saalburg. Maria acts as an agent for them, as well as designing her own projects with her business partner Nel Brett. When in need of a break from work, the couple can always go for a stroll, jog round the rest of the roof or simply lie on the lawn for a snooze. The rambling garden, with its honeysuckle and roses is well established and on warm days with all the glass doors open, the house and garden blend into one, so much so that a contented pigeon was recently found nesting under the radiator grill in the living room.

Adam and Maria have plans for the remainder of the roof, as the current house covers only half of it. Plan- ning permission was granted for an additional dwelling, some years ago, although, at the height of Prince Charles's carbuncle outburst, the planners stipulated that any new building should have a pitched roof with slate tiles, even though it would be seen by no one. One day they will reapply and let's hope the planners will share some of the vision of Nicholas Hills and let the next generation create an innovative contemporary home which has the brio of what went before.

! Retrouvius architectural reclamation and design can be contacted on 0171 724 3387