The Sainsbury Centre weighs 5,619 tons. Norman Foster knows that now, but on the day that Buckminster Fuller asked him the question, Foster had to go home and do some calculations. 

“I wrote a letter back to him. I made some very interesting discoveries because in the course of finding out how much the building weighed, I realised the disproportionate amount of weight that was located in the least attractive part of the building, which was the service basement. And of course the smallest amount of weight was in this great hall for displaying works of art and teaching.”...[+]