855773644-LEED-v5-BD-C-Reference-Guide-Launch-Edition - Page 305

Extracted Content

• Path 1 leverages passive building modeling tools to document peak thermal load intensities below the required thresholds.

  • Path 2 leverages ASHRAE 90.1 trade-offs for the prescriptive method to show a reduction in peak thermal loads below a referenced baseline.

  • Path 3 leverages the ASHRAE 90.1 Appendix G Performance Rating Method to show a reduction in peak thermal loads below a referenced baseline.

For all three paths, the referenced tools can be used to inform an integrative design process and make design decisions that holistically reduce peak thermal loads. The analysis should reflect the savings from the strategies referenced in Options 1–3 and further savings for any other load reduction strategies incorporated in the building design, such as improved insulation, improved window performance, or lower internal loads.

Preconditions applicable to all paths

Projects pursuing Option 4 must comply with all the following:

- **Ventilation loads** : When calculating peak heating and peak cooling loads, account

for ventilation loads. Use the design of outdoor air from the project’s design documents.

- **Measured Air Leakage** : During construction, provide air leakage testing to measure

the building’s air leakage and use the measured air leakage to calculate peak loads. If evaluating credit compliance during the design phase, perform the peak load calculations using the targeted air leakage that aligns with project design documents. Recalculate during construction if measured air leakage exceeds targeted air leakage.

Measured air leakage must be less than or equal to the ASHRAE 90.1 required air leakage rates.

For Path 2, this measured air leakage requirement only applies to envelope loads calculations, not ventilation loads calculations.

- **Balanced Ventilation** . Maintain the project’s ventilation and exhaust airflows within

10% of each other (see Option 1 Balanced Ventilation requirements).

PATH 1. PEAK LOAD INTENSITY

Path 1 requires projects to limit peak thermal loads below the specified thresholds.

U.S. Green Building Council LEED v5 Reference Guide for Building Design and Construction, April 2025 Launch Edition 295