New LEED v5 Rating System Includes ASHRAE IAQP in Prerequisite Requirements for Ventilation Design

Building owners and operators are always looking for opportunities to save money on new HVAC systems, improve energy efficiency, and maintain indoor air quality (IAQ). Many owners and operators also look for ways to earn additional points under the U.S. Green Building Council’s (USGBC) Leadership in Energy and Environmental Design (LEED) certification program. With the newly ratified LEED v5, all these goals are now possible by simply applying the latest version of ASHRAE’s Indoor Air Quality Procedure (IAQP).   

To achieve LEED certification, a project earns points by adhering to prerequisites and credits that address carbon, energy, water, waste, transportation, materials, health and indoor environmental quality. Projects go through a verification and review process by Green Business Certification, Inc. (GBCI) and are awarded points that correspond to a level of LEED certification: Certified (40-49 points), Silver (50-59 points), Gold (60-79 points) and Platinum (80+ points).  

The process of attaining LEED certification can be long and costly, and owners and developers are always looking for a shorter and less costly path to certification. The newest iteration of LEED offers just such a path with the explicit inclusion of IAQP as a ventilation prerequisite.

In March 2025 the USGBC membership ratified the next version of LEED, making significant updates to bring LEED in line with the most up-to-date design standards, including the use of ASHRAE Standard 62.1-2022 as the basis for ventilation design. LEED v5 now includes the latest version of the ASHRAE Indoor Air Quality Procedure as a prerequisite option when specifying minimum ventilation rates as well as the option to earn up to 2 points for enhanced designs. This is the result of extensive ongoing work by the USGBC over 10 years to establish a viable path for designers to use the IAQP on LEED projects. Lessons learned from multiple previous pilot credit iterations (EQ pilot credits EQpc68, EQpc124, and EQpc165) have helped shape the newest design path under the EQ prerequisite: Fundamental Air Quality.   

The inclusion of the IAQP as a prerequisite design pathway is also a direct response to a push from design engineers to implement air cleaning strategies that improve ventilation efficiency, which is enabled by the IAQP. Previous pilot credits were intended to motivate ASHRAE to address gaps in previous versions of the IAQP, which ASHRAE did with updates to the IAQP published in Standard 62.1-2022 in September 2022 and the subsequent Addendum n to Standard 62.1-2022 published in March 2023. Building on these important updates to the IAQP, the new LEED design pathway for IAQP is now fully aligned with the requirements of 62.1-2022. 

There are many benefits to using the IAQP rather than the alternative Ventilation Rate Procedure (VRP) to meet LEED Indoor Environmental Quality requirements. These benefits include smaller and less expensive new HVAC systems, lower energy use and carbon emissions from less conditioning of outside air, lower operating expenses from less energy use and lower peak demand, and increased resilience to polluted outside air.

In addition to these tangible benefits, LEED v5 also grants the project team up to 7 additional points under Indoor Environmental Quality (EQ) and Energy & Atmosphere (EA) depending on how they choose to deploy air cleaning. 

EQ credit: Enhanced Air Quality (EQc1) 

Under Option 2 (Enhanced Indoor Air Quality Design), designers may earn an additional point using enhanced IAQ targets that go above the minimum requirements of ASHRAE 62.1-2022. This design option is a direct alternative to the approach in Option 1 of increasing outdoor air rates by at least 15%, which would require additional energy and capital investment.   

EQ credit: Air Quality Testing and Monitoring (EQc5) 

Option 1 (Preoccupancy Air Testing) enables designers to earn an additional 1-2 points by undertaking preoccupancy indoor air testing after construction ends. Projects can earn 1 point for achieving design limits for particulate matter and inorganic gases, and 1 point for achieving design limits for volatile organic compounds. The test methods and instrument requirements are aligned with ASHRAE 62.1-2022 Section 7.3, with an additional number of measurements beyond the requirements of ASHRAE. 

EA credit: Enhanced Energy Efficiency (EAc3) 

Option 2 (Energy Simulation) utilizes whole-building energy modeling to evaluate the energy performance of an IAQP with air cleaning design, compared to a baseline model complying with the VRP and its higher outdoor air requirements. By simulating both scenarios, design teams can quantify the energy impacts of reduced ventilation rates allowed under the IAQP. On average, IAQP-based designs demonstrate approximately 12% energy savings relative to VRP-compliant models. These modeled savings can support up to 4 additional points under Enhanced Energy Efficiency.  

The LEED v5 inclusion of the IAQP creates an easy, cost-effective pathway for project teams to earn additional LEED points while realizing all the benefits of the IAQP. For owners and operators who want to achieve these benefits without going through the LEED certification process, one can always apply the IAQP without applying for LEED points.  

For more detailed information about LEED v5, see enVerid’s data sheet on LEED credits for Sorbent Ventilation Technology.