I cannot work and listen to Wagner at the same time, nor Mahler, nor Beethoven's late quartets. I enjoy listening to Chopin's piano music when I work.

I haven't taken any new projects in the past years - I told myself, if I cannot live long enough to finish it, I don't want it.

Qatar does not have much history, it's a new emirate. So I couldn't draw on the history of the country; its history is really just being a desert. But I thought, the one thing I must learn about for this project is the Islamic faith. So I read about Islam and Islamic architecture, and the more I studied the more I realized where the best Islamic buildings were.

My projects have typically taken a long time to complete. Buildings might take on average about five to seven years to finish, but in my case it's been longer, because the projects I have accepted within the past 15 years have been mostly government projects, and those involve some politics and funding issues, and approvals and so forth. So they're slower.

I believe that architecture is a pragmatic art. To become art it must be built on a foundation of necessity.

Luxembourg was and still is today a crossroads, the place where Germany meets the rest of Europe. The country lost part of its territory to Belgium in the 1800s, and during World Wars I and II the German military overran it. Very few people have visited Luxembourg - when I went there and looked at it, I said, my God, it's built on a rock. And within the rock they had a castle, and within the city there's a network of tunnels so the residents could move around and defend themselves. That was of great interest to me.

Architecture is the very mirror of life.You only have to cast your eyes on buildings to feel the presence of the past, the spirit of a place; they are the reflection of society.