A casual stroll through the shitamachi (low city) old quarters of Tokyo reveals any number of equally casual lean-to roofs and awnings. Further ahead, my favourite Chinese religious site, the Xuangongsi Hanging Temple, clings beautifully to a cliff face in Shanxi province. Similar cliff temples can be found throughout Asia and even in Japan: the Nageirido (Thrown-in Hall) of Sanbutsuji Temple on Mount Mitoku in Tottori prefecture, built almost 1,000 years ago in the Heian period and now designated a national treasure, props up its endearing little deck unabashedly on stilts.

All architectural constructs lean on the earth in one form or another. Lean-to structure are intimately related to the idea of autonomous architecture. Yet despite attempts to break free of public infrastructure, the Water Branch House is not exactly autonomous. Without the greater strength of nature it cannot stand. No matter how strong buildings are, they are weak on their own. After the 2011 Tohoku earthquake I realised we needed to humbly acknowledge our own frailty and brush up on the gentle parasitic art of building, and leaning. ”