Exterior, Wood Siding Material, Shingles Roof Material, and House Building Type A couple in Evanston, Illinois, asked John Issa of Perimeter Architects to add on a two-story, 650-square-foot addition to their traditional farmhouse. The new volume is clad in composite slate siding by Inspire Roofing Products; the windows are Pella.  Photo 2 of 6 in This Farmhouse-Style Home Gets a Clever and Geometric Update