Standard Guide for Building Enclosure Commissioning provides recommendations for the enclosure commissioning process from its project planning through design, construction and occupancy and operation phases. The commissioning process is outlined in ANSI/ASHRAE/IES Standard 202. However, enclosure retro commissioning (RCx) or existing building commissioning, a systematic process to improve an existing building envelope’s performance, can play an important role in energy efficiency of existing buildings. During this Building Envelope Tech Team Meeting, we discussed current practices in envelope Cx and RCx and we gathered Tech Team Member input on technical resources and action items taken to support application of envelope RCx.