* On Outlands, most crafted House Addons require, rather than two separate skills to craft, a single skill and one or more Crafting Manuals as ingredients for construction
* Crafting Manuals come in a variety of skills and require 100 Skill in that respective skill to craft (i.e. a player with 100 Carpentry can create a Carpentry Crafting Manual)
* Crafting Manuals require 1 Mastercrafting Diagram as an ingredient to craft
Crafting Manual
Source: Official UO Outlands Wiki.