<p>^I think it’s a different situation when there is a space crunch and other siblings are forced to share the room, as other posters pointed out. </p>
<p>In your case, it would be unfair for the one going off to college to have his room remain this temple of holiness while others are bunking and otherwise loosing privacy and a lot of comfort.</p>
<p>In the OP’s case, it seems unfair for the S - who already has a nice room and huge basement space - to be a hog and upset his sister so that he can have the basement AND the biggest room.</p>