Houses should have some extensions, but I don't know whether that would work in scripting, and with the current houses anyway.
On topic, I dislike the idea - it's bad enough that the one who finishes a house receives the key. Imagine this, you start building, collect supplies and so on, but are short 2 boards and have to leave. Next day, your house is finished and someone waves at you from inside - all your work gone. Now you have a house and fill it with furniture, carpets and supplies. All you own is in there, a collection or rate items and money, things with a rp-ist background for you, rare recipes, whatever. Now you can't sign on for a week or so, and didn't repair it in a while. Someone else comes by and repairs your house. While commendable, chances with your idea are that either it's a friend who will then be owner of your house and have to give you a key so you can enter your own house - or it's a not so friendly person (I believe you would say a "bastard"
) who will claim your house that way, devastate the insides, take your rare and valuable items and open the door for everyone else.