ABSTRACT
‘Air tightness’ is the property of building envelopes that is most important to understanding ventilation. It is quantified in a variety of ways, all of which typically go under the label of ‘air leakage’. In this chapter, we will review the state of the art of air tightness research. Before reviewing what is known about air tightness, we will summarize the key roles that air tightness plays in understanding ventilation.
