This work aims at identifying and proposing four prefabricated exterior wall elements to a company that will build small prefabricated houses where the house elements are produced in a Micro factory. The four wall elements are as follows: Corner wall units, wall elements with no cut-out for windows and doors, wall elements with cut-out for a window and door and wall elements with cut-out for a door. In this report four different prefabricated outer wall elements have been proposed for small housing project. A comparison study has been made between three different wall solutions (Outer wall solution two has been proposed by the students themselves as well as outer wall solution one and three from two different building suppliers, Isover and Paroc.) to ensure which of these walls fits the best for the four prefabrication element drawings. The main difference between the walls solutions mentioned above is that outer wall solution two has one thick layer of insulation with light beam rails and outer wall solution one and three has massive tree beams in them with separated insulation layers. The advantage of light rails compared to massive rails in outer walls is that the thermal bridges are minimized due to the fact that there are not as much exposed joints in the outer wall with light rails. One more big difference is that the U-value's differ between the three outer-wall solutions. Since the materials are different in the three outer-walls the sound insulation and fire protection characteristics also differ. The sound insulation and fire protection ability depends mainly on the amount of plaster boards and type of insulation in the wall. Outer wall solution two has been chosen for the house project and it will be the head characteristic wall ahead in this report. Outer wall Option Two) was chosen for the project. It was chosen due to following criteria's: low energy needs for active heating, low manufacturing costs, low U-value, low construction weight, good moist resistance, good sound reduction and high fire protection class.