855773520-LEED-v5-ID-C-Reference-Guide-Launch-Edition-1 - Page 123
Extracted Content
Proposed design: Allocation of shared systems For shared systems serving similar occupancies, allocate based on area served by the system. Multiply each shared system design parameter by the ratio of “total project floor area served” to “total gross floor area served.”
For shared systems serving dissimilar occupancies, allocate based on the proportion of total design capacity serving the project.
Equivalence to ASHRAE 90.1 Refer to the Project Priorities Library for regional paths addressing equivalence to ASHRAE 90.1.
For projects in the U.S., state or local codes are considered “equivalent” to ASHRAE 90.1-2019 or ASHRAE 90.1-2022 when the U.S. Department of Energy Building Energy Codes Program status of state energy code adoption indicates a commercial code efficiency category matching the referenced version of ASHRAE 90.1 or later for the project location in effect at the time of project permit application.
The 2021 International Energy Conservation Code ( IECC 2021 ) is recognized as equivalent to ASHRAE 90.1-2019 .
The 2024 International Energy Conservation Code ( IECC 2024 ) is recognized as equivalent to ASHRAE 90.1-2022 .
For both versions of IECC:
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IECC Section C407 Total Building Performance may be used to document prerequisite compliance only.
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IECC Prescriptive compliance (C402–C406) may be used in lieu of the ASHRAE 90.1- 2019 prescriptive method.
District energy systems (DES) ASHRAE 90.1 refers to DES as “purchased CHW” or “purchased heat” even when this energy is part of a campus distribution plant and not directly purchased from a utility or municipality.
Because DES systems are outside of the project scope of work, DES efficiency cannot contribute toward achievement of prerequisite compliance. Central hot water and CHW systems serving the Interiors project space may be treated the same as purchased heat and/or purchased CHW using this guidance.
U.S. Green Building Council LEED v5 Reference Guide for Interior Design and Construction, April 2025 Launch Edition 112