Wind - proof performance and importance of housewrap
Housewraps: Effective Air Barriers? Although a housewrap’s main job is to resist moisture and release water vapor (i.e., “breathe”), its role as an air barrier is becoming more important, thanks to stricter codes. The 2012 IECC raises air leakage standards for new residential construction, by requiring both blower door and visual inspection tests. A 2000 “cradle-to-grave” analysis by Franklin and Associates estimates that correctly installed housewraps can reduce the energy needed to heat and cool infiltrated air by 10 to 50 percent, yielding an annual energy savings of between 12 and 60.2 million Btu for a typical home. Taking into account the embodied energy of the product, this amounts to an estimated energy payback of between seven and 54 days. Though the air permeability of housewraps varies from product to product, non-perforated housewraps generally resist air penetration better than perforated versions.