UNUSUAL BUILDING CONSTRUCTION

Press, Volume XCVII, Issue 28766, 11 December 1958, Page 9

UNUSUAL BUILDING CONSTRUCTION

This is a hyperbolic paraboloid. A style of timber shell construction which is new to both Australia and New Zealand, it is the design chosen for a covered suburban market now being built at Pakuranga, Auckland.. The structure, which was designed by Michael Brett, as architect, and A. Macdonald, as engineer, has been described as all “skin” and no “bones,” akin to the cobweb and soap bubble. It is a method by which a deck of timber only inches thick can span 100 ft in a single, unsupported leap. The double twisted shell of .the hyperbolic paraboloid is a square with two ends touching the ground. These ends rest against reinforced buttresses or anchors which in turn are connected with high tensile steel cables to resist the outward pressure of the roof. A grocery shop dominates the area covered by the shell and is flanked by a butchery and green-

grocery to’place the three most important shopping activities under one roof with ample space for storage near to each display area. “The early history of the hyperbolic paraboloid is still somewhat obscure,” says Mr Brett. “Of the more generally known architectural examples it' would appear that the first occurred in the late 1940’s and early 1950’5. The form had been known and used in sculpture some time before that but probably the. complicated mathematics of the calculations deterred engineers from exploring its possibilities. “Hyperbolic paraboloids have been built in timber, steel, concrete and plaster. “The complete flexibility of internal arrangement is something which could be achieved only by more expensive and complicated structures. In the future the internal partitions can be very simply removed, the store rooms

built on to the back wall outside the main roof structure, and the usable floor space increased by about 75 per cent “The way the light is drawn into the centre of the building from the two high corners and the internal sweep of the double curvature of the roof are features which are immediately apparent. “AU this is not to say there are not problems. One has to make some provisions to prevent bodgies from riding their motorscooters up the buttresses and over the roof, and it will undoubtedly be the stock ‘delinquent's dare’ for years. “The preliminary work for the building was something of a headache since nothing like it had ever been done before in New Zealand. Access to anyone with knowledge of building of hyperbolic paraboloids was impossible."

Flexibility, said Mr Brett, must be one of the key characteristics of contemporary architecture.