Most energy benchmarking tools provide static feedback on how one building compares to a larger set of loosely similar buildings, without providing information at the end-use level or on what can be done to reduce consumption, cost, or emissions. In this article — Part 1 of a two-part series — we describe an action-oriented benchmarking approach, which extends whole-building energy benchmarking to include analysis of system and component energy use metrics and features. Action-oriented benchmarking thereby allows users to generate more meaningful metrics and to identify, screen and prioritize potential efficiency improvements. This opportunity assessment process can then be used to inform and optimize a full-scale audit or commissioning process. We introduce a new web-based action-oriented benchmarking system and associated software tool — EnergyIQ. The benchmarking methods, visualizations, and user interface design are informed by an end-user needs assessment survey and best-practice guidelines from ASHRAE.