The speakers during this Building America Webinar on Dec. 15, 2016, were Pam Cole, Pacific Northwest National Laboratory; Ari Rapport, IBACOS; and Robby Schwarz, EnergyLogic.

Air sealing of area separation wall assemblies is an identified barrier that limits the ability of builders to cost effectively achieve higher energy efficiency and quality levels in multi-family housing. Area separation wall assemblies that are tested and certified by UL have not been designed or tested for air tightness, and air leakage through these assemblies can be a barrier to achieving air leakage limits mandated by the International Residential Code (IRC) and International Energy Conservation Code (IECC). The 2012/2015 IECC mandates 3 ACH50 in climate zones 3-8 measured air leakage requirements for all units within multifamily buildings.

The Leadership in Energy and Environmental Design (LEED) certification program, ASHRAE Standard 189, and ASHRAE 62.2 all have comparable compartmentalization requirements. Fire-resistance rated wall assemblies (or area separation walls) have been identified as the major source of difficulty in air sealing/compartmentalization. Building owners are challenged with constructing to significantly tighter levels, addressing compartmentalization issues between units, and adopting test procedures to prove compliance.

Current efforts to engage with UL may address these challenges and provide a mechanism for code acceptance of air sealing methods for these area separation wall assemblies. During the webinar, the speakers discussed these challenges and current efforts to resolve them.

The webinar recording is also available.