As the world heats up, there will be an increased demand for air conditioning, especially in areas that typically haven't needed it (as well as in areas that typically haven't used it, even if it is traditionally very hot).
This can partially be mitigated by using building techniques that allow for passive cooling (and passive heating in the winter). But is there a way to mitigate it in existing buildings, particularly in private homes whose owners may not have a lot of money for retrofits?