[static_motion]

Depending on the region, "reasonably insulated home" really is the factor that makes this not so viable for a lot of people. In my Mediterranean-adjacent climate country, most homes are just not well insulated at all, and having heat running 24/7 during winter is extremely costly and inefficient even if the heating is on a low setting.

[looofooo0]

These home will most likely have a split air con, which will be the most efficient way of heating them. Also there is so much other room for improvement like drafty windows and doors etc.

[walrus01]

In many warmer climates, the mini split air conditioners sold are cooling capability only. This is much cheaper to purchase for a 12,000 up to 24,000 btu/h unit than one which is also capable of heating the interior.