Building with earth, a sustainable material for efficient buildings

The hygrothermal behaviour of a small building in a Mediterranean climate was studied by comparing three different solutions for the walls: concrete, fired clay and unbaked earthen walls. Several numerical simulations, with EnergyPlus, were carried out on the IEA BESTEST building. The evolution of the indoor relative humidity has proved that the unbaked earth significantly dump the fluctuations in indoor air relative humidity. This effect was generated by the better moisture buffering capacity of the unbaked earthen wall and by its lower water vapour resistance coefficient. The aim of the ongoing experimental research is to obtain a low cost-high performance building material suitable to achieve better indoor hygrothermal comfort in modern sustainable and efficient buildings.