What is the best building of the past 50 years?
I thought about Hunstanton, but in the end it has to be Scharoun's Berlin Philharmonie. Until then I had been convinced about the shoebox hall - the fan-shaped hall never worked acoustically. The Philharmonie is called a vineyard hall. St David's in Cardiff is one - it's where the audience is broken up in sections and you get fantastic reflections from these blocks and from the walls so you are getting a multiplicity of side reflections into the audience. The most recent was the Bridgewater Hall, a combination of the shoebox and the vineyard which I christened the Pangloss Hall, it being the best of all possible halls. But the Scharoun- I've sat in it and enjoyed simply wonderful music.
What is the most significant innovation of the past 50 years?
I don't think I've ever encountered a lot of innovation in structure: it has always been development.
Buildings are made of stone, sticks or mud, and not much has changed - although maybe we should add string. All we have done is to continuously refine these things.
And the best building product?
The HSFG bolt, the high-strength friction grip bolt. When I started life as an engineer you joined pieces of steel by riveting them. Then the black bolt took over. You used to design bolted joints for shear but you knew that the real connection was the friction between the plates. The HSFG bolt had a system in which you calibrated the tension and the friction between the elements and you knew exactly where you were.
What innovation do you hope to see in the next 50 years?
The big needed innovation is a personal, pocketable device to immobilise mobile phones within 100 feet of me, especially on trains.
Privacy is very, very important and will be the big issue.