The Low Carbon Futures Buildings are one of the key roles of reducing CO2 and obtain comfortable healthy living building spaces; in addition with the spread of the lightweight construction buildings the problem of overheating has been increased. This Paper is presenting the work on developing a unique wall panels for low/zero carbon Flat Pack buildings. A full scale test was presenting the effect of using a unique gypsum board with special thermal material to control the heat inside building spaces. In this experiment a Flat Pack unit has been divided in to two rooms, one of the rooms has been attached with the special gypsum boards. The results have shown that the difference between the both sides of the Flat Pack rooms between 3ºC to 5ºC depend on the outside temperature, wall location and time of the day. Thus, this extra layer will help to increase time lag and absorbing any extra heat which means controlling the temperature inside spaces to be the consequence of reduce the amount of CO2 by cutting the energy consumption.