Living Room, Chair, and Concrete Floor Pentimento’s true versatility is revealed with each new tenant who inhabits the structure. As Nicolas demonstrates, the polished concrete floors make for an ideal biking surface. When playtime is over, he hangs his bike on the wall by the front door, suspending it from the handlebars to keep the floor tidy.  Photo 9 of 10 in An Innovative Modular Building System in Ecuador