GB1
My proposal is basically a 6m x 4m house that is cheap due to construction materials cost and cheap labour and provides decent accomodation for 4-5 people.

Solution

The GB1 house is build in a cement area a bit larger than 24sqm. There is this metallic framework-structure that is connected to cement (or mud) base-floor and is used to provide the nessecary load security for the roof and for the installation of the wall panels. Wall panels are 1mx2m and are made of a layer of Extruded Polystyrene (EPS) between two layers of thin wood. The roof panels are made of two metalic layers that are filled with rigid insulation foam - polyurethane. The panels are connected to the iron structure using safety bolts. The latter design characteristic constitues GB1 as a modular housing product that can be build many times - anywhere in the world. This design also proposes an arrangement of furnitures and equipment for best accomodation.