This prototype ‘Zero Energy House’ is a house without fuel bills. The exceptional performance is achieved primarily by following the ‘Passivhaus’ principles of energy minimisation. Thereafter, renewable energy from roof mounted photovoltaic panels makes up the energy shortfall. Excellent indoor air quality is achieved by reducing air leakage and by providing ample fresh air which is filtered and heated via a heat recovery/ ventilation unit. The proposal has been evaluated by experts from the Building Research Establishment and the Passivhaus Institute in Germany.