Economy of space. You haz it.
Nope, I don't want to talk to you, I'm gonna go sit on my raft!
There is always always always room for more books. Keep it flexible.
Glad to see the former tenant didn't much the place up with taste or decorum.
This add-on is coming with us when we sell the place.
When you've only got about four feet of lateral space you have to get creative.
One of these days you're gonna wake up trapped upstairs because someone moved your stair block.