Energy models are constructed to ensure adherence to the energy code. They assess the proposed elements against a hypothetical (referenced) structure that meets basic code requirements. Beyond mechanical systems, a significant shortcoming in energy models often lies in the reduction of insulation effectiveness, attributed to substandard installation methods. We’ll examine various field images and delve into the nuances of insulation grading. We’ll also explore how Grades 1, 2, and 3 are defined, the criteria for their determination, and the impact each grade has on the overall energy model.