Adding character to a modern house, built originally for a Formula One world champion racing driver, meant adding something more lyrical to the rectangular form Architect Tom Pike knew the house as soon his clients took him to see it. It had been designed more than 30 years before by Broadway Malyan for whom Pike had worked for a while.
It had been built originally for racing driver Denny Hulme and had been reckoned a significant work of private-house architecture with the then-fashionable feature of hoop beams wrapping around the upper floor and roof of a two-storey rectangular plan - even if this was a sort of second-hand reference to a sort of industrial aesthetic along the lines of Mies's Crown Hall.
The plan was unusual in having the living room, bedrooms and kitchen all at firstfloor level with garage, spare bedroom, playroom and entrance at ground level. Pike's brief was, in part, to change the house from a boxy, rectangular form to something more voluptuous and lyrical. His response was to change the plan shape to an L by adding a new steel-framed double-height northsouth arm at the west end of the old house.
It is actually a vast, almost cathedral-like space with a multiple-swoop ceiling following the shape of the two roofs above. The north end is lifted up over a new garage and this upper level is a dining room and extension of the upstairs living room adjacent to a much expanded and relocated first-floor kitchen. Below is the new entrance in the west wall. A painted and stainless steel open staircase descends from this upper level down to the lower living room with its faintly Ronchamps-esque wall of deeply recessed windows on the west and a wall of glass overlooking the existing outdoor swimming pool terrace to the east. Pike developed a somewhat ogival cross section for the new roof above the old block which is extended over the north section of the new leg. This same swooping shape is repeated as a separate roof for the south half of the new leg.
The curved roofs are trapezoidal profiled steel deck with a silver-grey zinc coating.
Pike explains that there is practically only one place in the country that can curve metal like this. 'We had the steel channel sections bent - it's done on rollers - and then we had the decking curved to the same profile.When they were in place we used a flexible, glass-reinforced cement screwed to the underside of the curving frames and put insulation in the void. We use flexible grc quite a lot, especially for curved walls - and have used it for a section of curved wall adjacent to the entrance.'
Pike changed the character of the old building but maintained its overhanging first- and recessed ground-floor walls of glass overlooking the swimming pool. He reorganised the arrangement of rooms and, on the advice of structural engineer Timothy George, added a couple of columns to the leading corner of two of the timber hoop beams. He painted them grey and painted sections of blue engineering brick white.
Although it looks as if it was done effortlessly, marrying the original timber frame with the new steel frame was not without its difficulties in setting out and called for cosmetic treatment. But why a steel frame? Pike says: 'When you look at the shapes involved in the new block it is plainly the only thing we could have used. And the new block is actually a huge space with no internal shear walls and the wind loadings are relatively colossal. So the strength of the structure has to reside in its skeleton.'
The white rendered walls of the west end, with deep-set square windows, idiosyncratic eaves lines and clerestory windows, look as though they might be solid. They are actually quite thick - 100mm of blockwork either side of a 100mm cavity - but they are merely cladding to the underlying steel frame of regularly spaced steel columns that support both walls and the steelwork of the roof.
There is a lot of specialist steel: the balustrade to the edge of the semicircular balcony over the entrance door, the spiral staircase at the inner corner of the plan which leads down towards the swimming pool and the bravura painted and stainlesssteel staircase from dining room to ground floor with its semicircular landing. This latter has a floor of stainless steel perforated in a fan pattern. The special steelwork is the responsibility of McKays of Cambridge.
Pike says: 'McKays did everything to do with staircases and railing. And they did a superb job. They produced beautiful fabrication drawings. It's just what you want from a specialist supplier.'
It is not just McKay's work that Pike has singled out; he also praised main contractor H&H Construction. Pike says: 'It builds mock Tudor and Georgian for housebuilders and was the client's choice. But they were enthusiastic about doing something contemporary and did an excellent job. They are a small team based in Surrey whereas we tend to work in and around London. But we would love to work with them again.'