Post air-conditioning, European buildings are still built like that. Most housing buildings in Europe do not have air conditioning, even in the subtropical south.
Speaking of the south, many many buildings in Greece and Italy have a simple mirror and a steel tank on their roofs to supply hot water. No electricity or sophistication needed.
Even in the cold north, simple radiators provide enough heat to keep a house warm. Thick walls and small windows are enough to contain air temperatures in both cold Finland and hot Greece.
Speaking of the south, many many buildings in Greece and Italy have a simple mirror and a steel tank on their roofs to supply hot water. No electricity or sophistication needed.
Even in the cold north, simple radiators provide enough heat to keep a house warm. Thick walls and small windows are enough to contain air temperatures in both cold Finland and hot Greece.