Heavy weight or lightweight construction?
In general terms, the more mass there is within the thermal envelope the easier it is to control the possibility of overheating in summer months. A building with high thermal mass, exposed internally, will tend to have even temperatures and a good internal environment over the changing seasons. This does not mean, however, that we need to build all Passivhaus buildings in masonry: a timber frame construction with a solid ground floor (usually concrete on top of insulation) is often used and is a good way to provide thermal mass. In addition, the Passivhaus Planning Package (PHPP) will, of course, allow the designer to accurately design a shading strategy for any type of construction.