Oh, I thought someone might have explained -- sorry! This building is full of apartments, but nature has taken over most of them, so you have to fight the nature off to get rooms back. They're mostly unfurnished -- you need to trade with the gods to get furniture or, um, machines, or appliances and things. Or doors. Basically you need to either find someone who still has space and is willing to share, or claim an unclaimed but cleared apartment, or clear your own. They all have numbers or symbols on the door though.