ANSI/ASHRAE Standard 209-2018, Energy Simulation Aided Design for Buildings Except Low-Rise Residential Buildings is the product of a half-decade of inertia within the building design and construction community toward leveraging energy modeling a design tool through a project.
Standard 209 outlines the minimum requirements for providing energy design assistance using building energy simulation and analysis. To this end, the standard defines a range of minimum criteria from energy modeling requirements, to modeler credentials, to data reporting.
Adoption of the integrated framework offered by Standard 209 will better ensure the utility and accuracy of building energy modeling on a project by requiring project teams to adhere to stringent and standardized requirements.
The standard builds upon the notion of curating and refining a building energy model from conceptual design all the way through postoccupancy – a concept articulated by American Institute of Architects six years ago. (It is an approach that in many ways mimics the refinement of a cost estimate throughout the development of a project – broad at first, detailed in the end.) ASHRAE advances this notion by identifying eleven distinct “modeling cycles,” which occur at specific points in the development of a building project (see Fig. 1). Each modeling cycle is characterized by a specific purpose, applicability, and type of analysis. Project teams are not necessarily required to execute all eleven modeling cycles but as a collective, the modeling cycles clarify the definition of the building energy modeling exercises critical to each stage of a project’s design/construction/occupancy.