I have kids practically the same age, and we only just removed the toy box from the lounge yesterday. From now on, there is a small plastic dolls house in here for them to play with, otherwise they must play in their rooms.
They also are starting to learn that everything has it's place and when they have finished playing they MUST pack their things away. It's going to take a while for this to sink in completely but fingers crossed we get there one day. lol