[c3833174]

Mediterranean countries also get less harsh winters, especially in the last years people have preferred installing cheap stoves rather than doing all the work required to properly insulate buildings from the 60s (roof, external insulating coating, window frames, condensing boilers, etc).

[gravelld]

They also have more harsh summers. To an extent, in some cases, the vernacular protects them from that with high thermal capacity and decrement delay to buffer energy transfer. But if you then have a fashion for large windows... not so much.

And all that doesn't help with ventilation and maintaining healthy levels of fresh air.