To protect the paper from weather, Ban often covers it with acrylic. Coincidentally, his wife, Masako 　 an acclaimed accessories designer in Tokyo 　 calls her firm “Acrylic,” but that has nothing to do with her husband’s construction techniques. In conversations, Ban can be curt and snippy with a deft dose of impatience. Dressed in his signature wide black suit and black collarless shirt, he comes over as an angry priest (or “the nemesis of Clint Eastwood in a Spaghetti Western,” as a filmmaker once observed). Masako Ban assured me that, inside, Shigeru is different. So is the caterpillar, I thought 　 with its network of paper tubes and plywood it’s a rebellion in the making under a Teflon coat. Ban’s stringent ecological philosophy has influenced his plans for the Pompidou extension, which run against Renzo Piano’s thirty-year-old idea for an un-recyclable sculpture in praise of technology. It demonstrates a rebellious streak that may have been nurtured when Ban studied in New York with John Hedjuk, co-founder of the famed New York Five architecture group and preacher of an uncompromisingly pure form of modernism. In his role as eco-priest, Ban fills a void in today’s Japan: “a country for which I see no future!”

Walking through his office in quiet Matsubara district, with its winding stairways, contracted niches, unexpected corners and protruding bookshelves, one discovers another advantage of the paper tubes: if you hit your head here, at least you know you’ve probably done it on cardboard and not concrete!

ROLAND HAGENBERG  Under Article 38 of the Building Standards Law, the Ministry of Construction in Japan approved your paper-tubes in 1993. Since then you have used paper legally as structural material in buildings. How did you come up with that idea?