Consulting engineers are in search for applicable design guidelines to prevent down draught in newbuiltand renovated buildings.Downdraught is the air flow close to a cold surface, resulting from density differences between warm and cold air(buoyancy forces). Assuming a conservative design in practice, there is a possibility of wasting materials and energy. Next to that, it is difficult or even impossible to predict the air flow in a room due to downdraught. The same counts for assessing such a non uniform environment in terms of thermal comfort. As a result, the focus in this research is on downdraught and effective measures to assure thermal comfort near glass façades.