The Passivhaus standard in Southern Europe

More than 8.000 homes have been built to the Passivhausstandard in central Europe. The success of Passivhaus is due in large measure to it being a well defined product, understood by the developer, architect and future owner. However the Passivhaus standard was born to respond to the requirements of a relatively cold region. The EIE funded Passive-On project has examinedwhat elements of the standard could be useful in promoting the diffusion of low energy house design in southern Europe. On the one hand numeric modelling has shown that in Italy and the South of France the solutionsutilised in the central European Passivhaus, can with suitable modification, provide an effective basis for providing cool homes in summer. However on the other hand though the solutions may work, the implicit and explicit requirements of the Passivhaus standard can nevertheless represent over engineering in warmer climates. For example the Passivhaus standard makes an explicit requirement to limit the permeability of the building envelope (n50 < 0.6 h-1) which makes an implicitneed for active ventilation. However experience, for example from Spain and Portugal, shows that effectivelow energy homes can be built without the need for ventilation systems. The paper discusses the results of the numeric modelling showing how, with suitable adaptation, the passive design applied in the central EuropeanPassivhaus can be effective in providing comfortablehomes in Nice, Carpentras, Milan, Rome and Palermo. The paper also presents changes proposed to the current Passivhaus standard to allow designers in the southern Europe to employ alternative passive designswhilst ensuring that these provide guaranteed resultsin terms of energy and indoor comfort.