When we first looked at apartments here, I wasn't crazy about how they all seemed so compartmentalized. I prefer open spaces, but every apartment we saw had doors on every room, so every area was able to be shut off.
Now that the weather is colder I understand why this is a really necessary feature. Buildings here have very little (if any) insulation (although I hear this is starting to improve with new construction), so when it's cold outside, it's cold inside! Also, there isn't central heating/air conditioning - so this is what keeps us warm or cool:
There is one of these units in each of the bedrooms and in the living room. So we layer up, shut the doors in whatever room we're in and try to make trips out of them as quick as possible!