Quote Originally Posted by Silverraptor View Post
Tried this, didn't work. It says that item parameter cannot be found.
OK, that means the reference is wrong. I just tried it myself and it worked, so... the likeliest answer is that Hearthfire has an unexpected position in your load order for some reason.

Go find Lucia, open the console again and click on her. The first two digits of her ID are the same as the first two digits of the bedroom ID you need to install.

Unfortunately, I couldn't adopt her after installing the bedroom this way. But if you've legit bought the room from the steward, it may still work for you.