New Delhi, June 29 -- London melted this weekend, with pavements feeling like 57 degrees Celsius. India, imperfect as it is, can teach the United Kingdom about resilient housing. If you have been to Ladakh or even Garhwal, older homes were made of thick walls and a roof with multiple layers, making it possible to trap a pocket of air. This worked in summer and winter, as most heat is absorbed through the roof and the western wall. When I called architects familiar with such buildings, they shared the science behind the thick-walled houses I was describing. In the winter, the warm air trapped in the roof was let into the house, warming it slowly and storing heat via double-glazed windows. In summer, the same heat came in but was released via...