855773644-LEED-v5-BD-C-Reference-Guide-Launch-Edition - Page 233

Extracted Content

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 chilled water. Model HVAC systems for the baseline building design from the criteria in ASHRAE 90.1-2022, Addendum a, 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: Linked credits

EAc3: Enhanced Energy Efficiency . Use Method A for prerequisite compliance if crediting DES efficiency towards the project performance in EAc3: Enhanced Energy Efficiency.

EAc4: Renewable Energy . In the energy simulation, use submetering to distinguish onsite fuel from the modeled fuel for the district hot water plant. This information informs the EAc4: Renewable Energy, Renewable Energy Attributes, Project Energy Source criteria .

METHOD B. DIRECTLY MODEL PURCHASED HEAT AND/OR PURCHASED CHILLED WATER

Apply the PRM requirements to model purchased heat and/or purchased chilled water 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 district energy sources serving the project, derive these purchased energy rates and/or conversion factors as follows:

U.S. Green Building Council LEED v5 Reference Guide for Building Design and Construction, April 2025 Launch Edition 223