ASHRAE Standard 100, Energy Efficiency in Existing Buildings, is an ASHRAE Standard aimed at increasing existing building energy efficiency through the use of best operation and maintenance procedures, evaluation of actual building energy use, and verified energy performance improvements. Most buildings seeking compliance with Standard 100 must compare their energy performance with established energy use intensity (EUI) targets. Under Standard 100, buildings that do not already meet their designated EUI target are required to conduct an energy audit, implement efficiency measures, and prove that their new EUI meets the target. While Standard 100 allows for local jurisdictions to develop their own EUI targets, it also provides a table of default energy targets for commercial buildings that are based on the Commercial Building Energy Consumption Survey (CBECS) and energy modeling.

This paper derives localized Standard 100 EUI targets for 11 United States cities across 7 climate zones using local benchmarking data collected through annual building energy benchmarking ordinances. These localized targets were compared to the default energy targets available in Standard 100. Nearly half of the targets developed were within 20% of the default ASHRAE Standard 100 energy targets. Large differences between the default and localized targets indicate that (1) localized development of energy performance targets can better align building performance targets with energy efficiency or greenhouse gas emissions goals, and (2) the default Standard 100 energy targets may benefit from future refinements.