According to Jim Episode 2.05 The Closet

Jim asks Cheryl not to intrude his space in the bathroom sink and in their closet, claiming she takes up too much space, and worse, HIS space. Cheryl tries to do something about by getting rid of some of her stuff, but Dana tells her it's time for women everywhere to show men they also have a need for space. Therefore, instead of doing what Jim asked her to, Cheryl buys even more clothes to jam up the closet. As a revenge, Jim decides to decorate their room in his own way. That starts a feud between them, until Jim falls down from the attic on their bed, breaking through the ceiling. He tells Cheryl that he needs his own space, and not because her stuff annoys him, but because he has the need to feel safe from the world sometimes. They settle their feud and agree on respecting each other's spaces.