There is not a direct correlation between the EPA score and ASHRAE 90.1. EPA's Target Finder score is a performance measure based on actual operating building data taken from DOE's Commercial Building Energy Consumption Survey (CBECS). ASHRAE 90.1 compares the regulated energy of a proposed design with the regulated energy of a baseline model, both meeting all of the prescriptive requirements of ASHRAE 90.1.
ASHRAE 90.1 requires evaluating the energy demands and costs of the heating, cooling, lighting, and other systems of the proposed design and comparing that to the comparable figures for a base building design that meets ASHRAE 90.1 prescriptive requirements. This means that two designs that meet the same programmatic requirements could have different 90.1 ratings: one could be 20% better than 90.1, and the second could be 30% better. This could arise because the design strategies and technologies proposed by two firms could differ. In contrast, Target Finder's score provides a unique value for a facility in a specific location with specific programmatic requirements.
The EPA energy performance scale is derived from actual building data taken from DOE's CBECS. A 75 rating at a specific location for a building with certain property use details (square footage, occupancy, etc.) will have a set value. EPA's score is relative to a large population of operating buildings, rather than a measure of one design vs. a base design.
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