The full list of items is located at C:\steam\steamapps\common\Life is Feudal Your Own\data in the object_types.xml file, find the item ID and spawn it in GM mode.
Or just GM spawn the decorator kits. Control ~ to get into the console, /gm (password) to get into GM mode, and use /additem 1634 or whichever to spawn it in your inventory. To just spawn the building itself use /addobj (id number) but you will have much finer control over placement by actually building it. Or at least start building it and use /complete to finish it while it is targeted.
1634 Novice Decorator Kit
1635 Apprentice Decorator Kit
1636 Master Decorator Kit