For this project, researchers sought to investigate and develop strategies to improve the area separation walls (ASWs) or shared interior walls of townhomes. A tension exists between the requirements in the International Energy Conservation Code (IECC) for air sealing and requirements in the International Residential Code (IRC) for fire-rated assemblies between townhomes, which causes significant challenges in both construction and code enforcement.

Energy code provisions save consumers energy and reduce utility bills, but they also require additional steps to test for and achieve specific air leakage rates through the building’s thermal envelope. Consistently achieving cost-effective ASWs in townhomes that meet the fire protections in the residential code and air tightness requirements in the energy code can be a challenge for builders, architects, trade contractors, and code officials. The authors propose nine strategies, including both regulatory and technological strategies, that builders can use to ensure that ASWs are air sealed and maintain proper fire rating.