An apartment in Sofia Bulgaria. 600m altitude quite “near” Greece. In case the wing blows from north it gets colder in the winter. In case it blows from the south than it worms up. Basically like real cold can’t last because the wind direction changes constantly. The walls, the slabs can’t accumulate “lots” of cold. The owner usually gets home at like 7 pm. The mountain Sun, being almost in Greece and having all of the windows facing South is an advantage. Opening the shades and curtains daytime lets the apartment heat up naturally. Air leakage pressure differences let lots of heat slip out of the house. Because nobody is at home all day running a city managed central heating system or hot water makes no sense. The bathroom is somehow in the core in the building so that never gets cold. Here the workflow is the following.
The owner knows when he gets home so with a simple 4 dollar automation system starts the boiler 1h earlier of the arrival. In the apartment is not worm but its not that cold. The second of the arrival it starts the 2 air conditioners in the rooms while the shower is prepared. Now shutters are closed so windows don’t loose that much of the heat. After a few minutes of functioning air conditioners could be closed most of the time. When Northern winds dominate (in January or February you might use them longer) but the overall they consume insignificant.
At 10pm air conditioners stop even in the coldest weather. The apartment slowly cools down to perfect sleeping temperatures. In the morning only one air conditioning system is used for a few minutes at most. to be poetic here : the quest is not finding the perfect spouse. The quest is to find the perfect spouse for you. The same boiler, air conditioning driven solution (at the neighbors) would be a total disaster. It would cost a fortune to operate.