In my one house, the main section of the main floor has no ceiling to create a balcony affect from upstairs and I have noticed that since the lights don't come on on automatically when in that room (since they're hanging from the ceiling upstairs). So that would make sense except that they don't always change into their winter clothes. And when they go down into the basement lounge, which has a full ceiling, they still change into their winter clothes to go down there. My upstairs has a full ceiling as well. Only the balconies have partial ceilings.