855773520-LEED-v5-ID-C-Reference-Guide-Launch-Edition-1 - Page 124

Extracted Content

For projects that use the ECB method, model purchased heat and/or purchased CHW as independent energy sources using the same utility rates per unit of energy for the ECB and design energy cost models.

For projects that use the PRM, use one of the following modeling methods to document the DES:

METHOD A. ASHRAE 90.1-2022 ADDENDUM A. (Removes inherent DES Penalty)

The project may apply ASHRAE 90.1-2022, Addendum A to either the ASHRAE 90.1- 2019 or ASHRAE 90.1-2022, Appendix G criteria as applicable to avoid the inherent penalty in the Appendix G PRM Performance Index Targets when modeling “purchased heat” and “purchased CHW.”

Model HVAC systems for the baseline building design per ASHRAE 90.1-2022, Addendum A criteria as if all heating and cooling generation equipment is on-site.

Model the proposed design with natural gas forced draft boilers in place of district heating and water-cooled chillers in place of district cooling, matching the type and number specified in Addendum A. For projects using ASHRAE 90.1-2019, replace all ASHRAE 90.1-2022, Addendum A references to Section 6 prescriptive criteria for the proposed building design with ASHRAE 90.1-2019, Section 6. Additional Considerations

Additional considerations: Linked credits

EAc2: Enhanced Energy Efficiency . Use Method A for prerequisite compliance if crediting DES efficiency toward the project performance in EAc2: Enhanced Energy Efficiency .

EAc3: Renewable Energy . In the energy simulation, use submetering to distinguish fuel used on-site from the modeled fuel use for the district hot water plant. This information is necessary to inform the EAc3: Renewable Energy, Renewable Energy Attributes, Project Energy Source criteria .

METHOD B. DIRECTLY MODEL PURCHASED HEAT AND/OR PURCHASED CHW. Apply the PRM requirements to model purchased heat and/or purchased CHW as independent energy sources in the baseline and proposed design, with the same utility rates or source energy conversion factors for the baseline and proposed design. Use published utility rates or source energy conversion factors when available. Otherwise, if purchased energy rates or source energy conversion factors are not published for the

U.S. Green Building Council LEED v5 Reference Guide for Interior Design and Construction, April 2025 Launch Edition 113