HVAC solves climate control. By that measuring stick, I have been routinely disappointed by indigenous structures that claim to have solved climate control but should more accurately be described as "somewhat mitigating the worst of it at enormous cost to the builder, maintainer, and/or operator." They have a lot more in common with the poorly functioning "thermal battery" than with modern HVAC, which is boring, cheap (by comparison), reliable, flexible, and doesn't even require computers -- a bimetallic strip will do, if you must.