No, you are right WoT - your idea to use two small one is great but I only have a 5 to last the whole castle and I would need four of these. I have plenty of the 1x2 unit fillers so I will just cut one of them in half
Couldnt you just buy a house and get one or more of those pieces? Besides, for use Medieval collectors houses are very good to have. Hope you like the outcome of your custom Flatcat.