I know this was over a year ago, but hopefully..... When I go into Edit - Default Settings - Walls I see Exterior and Interior and the ability to select different types but not the ability to change the materials. So I can use Brick-6 or Siding-6 but I can't change what type of siding. In Edit - Default Settings - Materials, there is no item "Exterior Wall". I would very much like to change the default siding used but can't find where to do this.