Exterior, Metal Siding Material, Metal Roof Material, Wood Siding Material, Prefab Building Type, and House Building Type Salem, Oregon-based Ideabox approaches prefabricated homes from a modern and sustainable point of view, seeking to build prefab residences that are beautiful, efficient, and affordable. With 9 basic types that can be customized, the homes start at 400-500 square feet and reach about 1,600 square feet. Each home is built with open-web engineered trusses, insulation with high R-values, dual pane low-e windows, and EnergyStar-certified appliances.  Photo 5 of 7 in 7 Prefab Companies That Oregon Dwellers Should Know