Modern Architecture and Ventilated Double Glass Façades (VDGF) are often related with each other: the use of enormous quantities of glass, steel and concrete are essential ingredients. VDGF could be briefly defined as façades consisting of two skins (completely transparent or not) with a very particular ventilation strategy. The acoustical European standard EN 12354 (2000) offers the possibility to predict façade insulation and insulation between rooms inter connected with a cavity. It has been concluded from this study that VDGF have an acoustical façade insulation that is far better (up to 10 dB) than that of traditional façades (office buildings). The special ways of ventilating the building and the ‘doubling’ of the skin of the façade play an important role. On the other hand due to transmission of sound through the cavity of a double façade, the acoustical insulation between rooms (on different floors) situated at the façade side, is lower compared to buildings with the same internal construction but with no cavity (values up to 8 dB), when no special measures are taken to prevent the (airborne) indirect transmission. To achieve good calculation matches, some modifications were introduced in the standard, i.e. the calculation per frequency band, taking into account either the “Mass-Spring-Mass” or the “Three Rooms model” depending on the frequency band and adaptations concerning free field conditions.

We refer to: www.bbri.be/activefacades.