(5) For Federal buildings for which design for construction began on or after April 7, 2023, each Federal agency shall determine energy consumption levels for both the ASHRAE Baseline Building 2019 and proposed building by using the Performance Rating Method found in Appendix G of ASHRAE 90.1-2019 (incorporated by reference, see § 433.3 ). The formula for determining the percentage improvement shall be as follows: Percentage Improvement = 100 * (1-PCI/PCIt)
Where
PCI = Performance Cost Index calculated in accordance with Section G1.2 of ASHRAE Standard 90.1-2019
PCIt = Performance Cost Index Target calculated by formula in Section 4.2.1.1 of ASHRAE Standard 90.1-2019