Project Brief: This new house is aiming to be Code for Sustainable Homes, Level 6 , on the model of the German PassivHaus (Zero Carbon). * A PassivHaus is an ultra low energy house. It is planned and constructed so that there is very little space heating energy demand, and this can be distributed by the comfort ventilation system alone. * A building of this standard offers high levels of comfort and very low energy consumption, together with very low running costs, and the potential for zero carbon emissions.