We have a room that serves many purposes. We call it the Room of Requirements (if you've read Harry Potter you will recognize the name). During our kitchen project it has served as a staging and storage area for the project. Here it is full with the kitchen project stuff. There is even more stuff than you can see. Most of the kitchen furniture was stored in here as well as the Vent A Hood and the cook top.
It has also served as my craft room. A guest room. A play room when we were taking care of twin boys. During rare lengthy summer hot spells, we've slept here. We haven't had to do that for a few years since we haven't had a long enough hot spell to need to do that. Here it is set up as a bedroom.
It's really nice having the luxury of a room we can use like that. Of course, we could just call it the spare room. But Room of Requirements is so much more fun.