Since it was first conceived, ASHRAE Standard 209 has balanced being a minimum compliance standard and a best practice guideline. Broken into 11 modeling cycles, the standard covers all phases of a building’s life cycle, from design to construction to operations. The 2024 version includes updates that clarify its purpose and requirements as a standard and provides several informative appendices to provide guidance for modelers looking to do more than the minimum.

This presentation will provide an overview of ASHRAE Standard 209’s purpose and structure. Major updates in the 2024 version will also be presented, which include refinements to the body of the standard as well as guidance in the form of informative appendices. Attendees will then participate in one of four break-out groups to discuss the topics presented as well as overall improvements to be incorporated into future updates. The success of this standard and its implementation rely on the adoption by building performance simulation professionals and their respective input. This session offers the opportunity to close the feedback loop in the standard development process.