It's very geology dependent, but they do this in Coober Pedy, a town in Australia where underground building is common for cooling reasons. https://en.wikipedi

It's very geology dependent, but they do this in Coober Pedy, a town in Australia where underground building is common for cooling reasons. https://en.wikipedia.org/wiki/Coober_Pedy https://en.wikipedia.org/wiki/Coober_Pedy I don't think it's something we will transition to in general "for survival" though. Building regulations should just catch up and enforce appropriate insulation levels and building methods for the given environments.