Would this be better as features you buy for a castle room, which otherwise wouldn't support the special actions of these items? For instance, marking a room as a 'library' would allow you bookshelves; a 'study' would allow chairs and desks, a 'foyer' would allow couches and lounges, etc. Or is it something that should be skill dependant and can work anywhere it's set down? Or is it something that should be forgotten completely?
More things to use to express yourself (and your environment) the better. I wouldn't forget about this.
I wouldn't say that this is a huge thing. It would be fun. I'd use it. I don't think one should have to "mark" rooms to enable certain things. It feels restrictive...what if I want a bookshelf in my study? Or a desk in my library? It seems like an unnecessary set of restrictions, to enable only certain furniture in certain rooms.
The "library" and bookshelf idea DID get me thinking: What about allowing bookshelves, in castles, that can hold player-made books? Instead of wizards having to hard-code books submitted by Garkin, how about players being able to buy "blank books" (like the blank scrolls that exist) and players can write in them. Perhaps allow functionality for adding pages, where each page acts a bit like scrolls do now. And perhaps make a way to duplicate them (perhaps at a cost...Gutenberg comes to Darke) so that books can be distributed...for free, as a saleable item (if any of us are good enough writers that people would pay mcgrail to read what we produce), whatever.
If the printing press idea is implemented, perhaps make that also a piece of furniture that can be bought or made in a castle. Or not. Just a thought to keep this more on topic.
Books fun.