Sims not changing clothes on Community Lot

I am having a small problem with a community lot I have made. When winter rolls around in the neighbourhood and I have my sims visit this community lot, they will not change from their outerwear to normal clothes when they enter the building. This happens to any sim who visits the lot. The only way I can foce them to change their their clothes is to put the coat rack on the lot and click remove outerwear. (But I can only do this with my sims and they will not automatically change back into thier outerwear when they leave) I looked around the lot seeing if I might have missed to close off a corner or wall, made triple sure there was a roof on the building and I still can't figure it out. Any one have any ideas why they won't change clothes upon entering the building?