855773520-LEED-v5-ID-C-Reference-Guide-Launch-Edition-1 - Page 228

Extracted Content

• Comply with the maximum air leakage thresholds referenced in Table 1 of the credit requirements. These are more stringent than required by ASHRAE 90.1 for initial buildouts and aligned with the new buildings criteria from ASHRAE 90.1 for projects in existing buildings.

Projects in existing buildings:

• Conduct a pre- and post-alternation air leakage test. For this option, projects must improve the existing envelope such that leakage is reduced by at least 30% from the pre-alteration test values. The post-alteration value must be less than 1.0 cfm/SF (5 l/s*sq. m.) at 75 Pascals (0.3 in H20), even if this represents a reduction of more than 30%.

Air Leakage Testing Standards

Testing should conform to one of the referenced air leakage testing standards: ASTM defines air leakage testing criteria. ASTM E779 [53] uses the fan-pressurization method for testing. ASTM E3158 [54] provides a standard method for testing large or multizone buildings. ASTM E1827 [55] determines air tightness using an orifice blower door. Residential spaces in mixed use buildings may also apply ANSI/RESNET/ICC 380 [56] .

Option 2. Energy Storage

Projects are awarded points for installing on-site electric and/or thermal storage that meets capacity requirements, relative to peak demand, per Table 2 of the rating system.

For an all-electric project, the Table 2 thermal storage capacity thresholds that compare to peak coincident thermal demand are expected to achieve similar electricity demand reductions to the Table 2 electric storage capacity thresholds that compare to peak electric demand. This is because the peak electric demand includes the contribution of thermal demand and other loads such as lighting, plug and process loads, pumps, and fans.

Electricity storage refers to large batteries that store electricity until it is needed.

Thermal energy storage (TES) stores heating or cooling energy for later reuse. Examples include ice storage, CHW storage, and hot water storage.

53 “ASTM E779”, ASTM International, accessed March 31, 2025, https://www.astm.org/e0779-19.html. 54 “ASTM E3185”, ASTM International, accessed March 31, 2025, https://www.astm.org/e3158-18.html. 55 “ASTM E1827”, ASTM International, accessed March 31, 2025, https://www.astm.org/e1827-11r17.html. 56 “ANSI/RESNET/ICC 380”, ICC Digital Codes, accessed March 31, 2025, https://codes.iccsafe.org/content/RESNET3802019P1.

U.S. Green Building Council LEED v5 Reference Guide for Interior Design and Construction, April 2025 Launch Edition 217