Yep, I've lived in old buildings most of my life (very german predilection for the "Altbau" I guess) and I'm not sure whether people are aware how much energy it costs.

I love 3.5m ceilings and 2.5m high windows, I love thick walls made from solid stone, that's how I grew up, in a rented place in a wonderful turn-of the century building. ... it's not even expensive to rent compared to where I live now. But heating alone costs enough that it could pay for a single room somewhere else. And given that the walls are thick, but not insulated, you have to make sure you heat it, make sure you don't put things too close to the wall, otherwise you might have to battle moisture and moldy walls. In fact, if the windows insulate too well it might even be a drawback because the moisture can't escape, and you have to air the rooms (the very german habit of "Stoßlüften") frequently to not get mold.

The rectengular zero-energy buildings of today, you probably don't need to heat much. Friends of mine used to live in a building like that. Well insulated, three-pane windows, all that. They barely had to turn the heat on in the middle of winter. Body heat, residual heat from cooking and what not, it's practically enough to keep the place warm.