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Do not claim trade-offs between the envelope and other energy-using systems. This sets a higher bar for the building envelope than EAp2: Minimum Energy Efficiency for projects documented using ASHRAE 90.1 Energy Cost Budget (ECB) or ASHRAE 90.1 Ap pendix G Performance Rating Method (PRM).

Envelope performance must comply with one of the following:

- _ASHRAE Standard 90.1_, Section 5.5, Prescriptive Building Envelope Compliance

Path.

- _ASHRAE Standard 90.1_, Section 5.6, Building Envelope Trade-off Compliance Path.

(Refer to EAp2: Minimum Energy Efficiency guidance on this topic).

Use the same version of ASHRAE 90.1 referenced for EAp2: Minimum Energy Efficiency (i.e., ASHRAE 90.1-2019 or ASHRAE 90.1-2022 ).

Option 1. Infiltration and Balanced Ventilation

This strategy reduces heat gains and losses associated with infiltration and exfiltration. Projects must provide testing during the construction phase to verify the achievement of both the balanced ventilation and measured air leakage criteria.

Balanced ventilation Design the building’s mechanical system and controls to support balanced ventilation airflow that maintains the building’s total supply ventilation airflow within 10% of the total exhaust airflow.

During construction, provide testing, adjusting, and balancing (TAB) of building air handling systems that verifies a ratio of ventilation to exhaust airflow between 90% and 110% on a whole-building basis.

Infiltration Design and construct the building’s air barrier to minimize air leakage through the building enclosure. During construction, provide air leakage testing to confirm the project achieves targeted performance levels (referenced in Table 1 of the credit requirements). The testing must conform to one of the referenced air leakage testing standards:

U.S. Green Building Council LEED v5 Reference Guide for Building Design and Construction, April 2025 Launch Edition 292