We could, however, both
in winter and summer,
have a comfortable temperature, say 25°C at home
and at work without spending not a drop of oil for
heating or cooling the space.
To achieve this it is enough to do what is called Pasivhaus.
To insulate the building
well, and renew the air in the rooms
by passing it through a heat exchanger.
That's all, and this should be done
as soon as possible.
If we were wise, of course.