What is the best building of the past 50 years?
The Sydney Opera House. It changed the way architects and engineers worked together and it set the scene in which I work. It is supposedly a piece of astonishing engineering, but it's a collaboration.
Between 1957 and 1961, the 'unbuildable' competition-winning architectural scheme was gradually bent to suit the available technology and analytical capacity.
What is the most significant innovation of the past 50 years?
Arup Associates' integrated practice of the 1960s and '70s. Since then the contribution of engineers has come to be more controlled by the architect's conception of what engineering should be.
What is the best building product of the past 50 years?
The continuous flight augered pile, invented in North America in 1953.
A great big corkscrew is driven into the ground and then slowly pulled out. As it comes up, concrete is poured down its hollow middle.
You don't need expensive casings because the hole is supported by the concrete going in. It's fast, cheap, perfect for weak and rotten ground and has been critical in the development of marginal sites.
Because they are sometimes sensitive to over-hasty operators, they are a good source of supervisory and practical training for young engineers.
What innovation do you hope to see in the next 50 years?
Engineers will make a contribution to sustainable building by focusing on lightness, elegance of use and the minimum of means. This will come about primarily from continued instrumentation and observation of real buildings and checking these against, for example, the original computer models. So the computer processing of data will be key in developing a database of actual building behaviour.
These interviews by Sutherland Lyall will form the basis of the 50/50 exhibition at Interbuild 2002.