He may have risen to prominence for his disaster relief architecture and deft use of recyclable materials, but Shigeru Ban describes his idiosyncratic use of material as an "accident." Speaking to The Wall Street Journal, the 2014 Pritzker Prize Laureate recalls turning to cardboard tubes as a matter of necessity. "I had to create a design for an exhibition," Ban told the newspaper, "But I couldn't afford wood. Instead, I used the many paper tubes from rolls of drafting paper that were lying around. The tubes turned out to be quite strong." The most prominent of Ban's cardboard tube structures is Christchurch's Cardboard Cathedral, built in the aftermath of an earthquake that devastated the city in early 2011. Read WSJ's full interview with Ban here.