Redefining Air Quality with LEED v5

LEED v5 BD+C Indoor Environmental Quality (IEQ) credits introduce a performance-driven approach to creating healthier, more resilient indoor spaces. This updated framework has a new emphasis on air quality monitoring, pollutant control, and occupant well-being, moving beyond static design requirements and building flush-outs.   

The IEQ credits have been restructured to emphasize performance, resilience, and occupant health. The category includes three prerequisites – Construction Management, Fundamental Air Quality, and No Smoking or Vehicle Idling as well as a handful of other pathways, including flexible options for enhanced air quality strategies and continuous air quality monitoring. Today, we’re going to dive into LEED v5’s EQc5: Air Quality Testing and Monitoring – what’s changed in v5 from v4.1, best practices moving forward, and the real ‘why’ behind these changes.

Air Quality Monitoring: v5 vs v4.1

LEED v5 marks a significant shift in how indoor air quality is evaluated, moving away from one-time spot checks toward long-term performance tracking. In LEED v4.1, the Indoor Air Quality Assessment credit allowed project teams to earn points through either a pre-occupancy flush-out or post-construction air testing. However, in LEED v5,the flush-out is no longer available – projects must now demonstrate that the building can perform through validated testing or continuous sensor-based monitoring of pollutants like CO₂, PM₂.₅, and VOCs. While a flush-out may still be considered to prepare the building for successful IAQ testing, it no longer carries direct credit value. This change reflects LEED v5’s push for real-time data and sustained air quality performance, reinforcing the importance of healthy indoor environments throughout a building’s lifecycle.

No more flush-out?

The purpose of the flush-out option in LEED v4.1’s Indoor Air Quality Assessment credit was to remove airborne contaminants introduced during construction and finishing before occupancy. By delivering a large volume of outdoor air through the building systems, the flush-out helped dilute and expel pollutants such as volatile organic compounds(VOCs), dust, and other particulates. This process aimed to create a healthier indoor environment for occupants at move-in, but it also allowed project teams to bypass performance-based analysis of the air quality within their space.  

As a building owner of a new development or an occupant within a commercial office building, would you feel safer in a space that:

• Performed a building flush-out prior to occupancy without data or any inferences on the air quality before / after the flush-out
• Performed indoor air quality testing for VOCs, particulates, and other inorganic/organic pollutants against recognized thresholds. Review data and adjust the space accordingly based on results before occupancy

Through air quality testing – whether that be continuous monitoring or onsite verification – project teams gain actionable data that creates an opportunity for project teams to make informed decisions and correct air quality concerns before occupancy. While flush-outs no longer earn points under LEED v5, they do remain a valuable preparatory step to help ensure successful IAQ testing and long-term building performance. The transition to performance-based verification marks a significant shift in the right direction for indoor air quality in the built environment.

A push for Continuous Monitoring 

LEED v5 places a strong emphasis on continuous air quality monitoring – going far beyond the traditional point-in-time spot checks traditionally used for air quality monitoring. Being able to track these pollutants throughout the building’s lifecycle allows teams to identify trends, respond quickly to issues, and maintain healthy air long after occupancy begins—something a one-time test simply can’t guarantee. It’s the difference between guessing and knowing, and it gives owners confidence that their spaces truly support health, productivity, and comfort over time.

Final Thoughts

LEED v5 is changing the game with new strategies and requirements within the Indoor Environmental Quality credits – moving beyond design-based compliance to performance-based verification, echoing WELL v2’s commitment to measurable health outcomes. Continuous monitoring and testing provide real-time clarity on indoor air quality, enabling informed decisions and proactive strategies. For building owners, this means confidence and control—knowing what’s in the air and addressing issues before they affect people. LEED v5 sets a new standard for transparency, accountability, and occupant well-being.