This standard is intended for the measurement of the air permeability of buildings or parts of buildingsin the field. It specifies the use of mechanical pressurization or depressurization of a building or partof a building. It describes the measurement of the resulting air flow rates over a range of in-door-outdoor static pressure differences.This standard is intended for the measurement of the air leakage of building envelopes of single-zonebuildings. For the purpose of this standard, many multi-zone buildings can be treated as single-zonebuildings by opening interior doors or by inducing equal pressures in adjacent zones.It does not address evaluation of air permeability through individual components.