As part of their support to the ASHRAE Standing Standard Project Committee (SSPC) for Standard 90.1, Pacific Northwest National Laboratory (PNNL) staff members regularly perform a progress indicator analysis to quantitatively measure the progress of Standard 90.1 through its three-year standard development cycle. With challenging energy reduction goals ahead of us, combined with significant savings already achieved, code developers wonder if we have reached a point of diminishing returns in advancing energy codes and standards.