Exterior, House Building Type, Wood Siding Material, and Flat RoofLine The mudroom is the project’s most customized component. Built on-site, it connects the house with two other Blu Homes prefab designs: an Origin studio, containing the gym/office, and a W-Series garage. James Hardie Reveal siding in Iron Gray distinguishes it from the factory-built modules, which are clad in Western red cedar.  Photo 9 of 9 in Park Place