In the spring of 2010 we developed and built an additional structure that functions as a multi purpose space. ProtoStoga it is a light-weight model. ProtoHaus weighs in at 9,500 pounds. A light-weight model (under 1,500 pounds) is easier to move at short notice and requires less fuel to transport. It functions as an extra bedroom where we may house guests, a reading room, a gathering space, a mobile vacation home, an office and more! At 40 square feet the ProtoSotga expands the livability of the ProtoHaus without adding too much to our carbon footprint.