Exterior, House Building Type, Wood Siding Material, Concrete Siding Material, and Flat RoofLine Designers Christopher Robertson and Vivi Nguyen-Robertson conceived their house as an unfolding sequence of simple geometric forms: a low concrete wall, a concrete cube, and a boxclad in Siberian larch.  Photo 3 of 17 in A Texas Couple Builds Their Cast-In-Place Concrete Dream Home