The evolution of Minnesota’s energy code continues to emphasize the critical role of air barrier performance in construction. Proper verification and documentation of these systems has become increasingly relevant for architects and builders working on commercial and institutional projects throughout the state.
Air Barriers and Building Performance
Air barrier systems are fundamental to building performance, with direct impacts on energy efficiency, occupant comfort, and long-term durability. According to NIST research, effective air barriers can reduce total energy costs by up to 36% in cold climates like Minnesota, with the greatest impact seen in heating costs (NISTIR 7238, “Investigation of the Impact of Commercial Building Envelope Airtightness on HVAC Energy Use”). These significant performance impacts make air barriers a critical component in high-performance building design and construction.
Air Barrier Verification
The 2024 Minnesota Energy Code now requires formal verification of air barrier systems to confirm their continuity. For most commercial buildings, this can be achieved through one of two pathways:
- Performance verification via whole building air leakage testing, as per Section 5.4.3.1.1
(or)
- Design and installation verification via document review and field inspections, as per Section 5.9.1.2.
Performance verification (pathway #1 above) occurs once construction of the air barrier systems is complete. Testing must result in an air leakage rate of 0.40 cfm/ft² or less for compliance. In the event that the building exceeds the maximum leakage, additional testing and repairs or modifications to the building envelope are necessary, which can be time and cost intensive. While this method provides quantitative air leakage metrics (which may be useful or necessary depending on the specific project goals), the risk of failing the initial test can be high without the guidance of an air barrier professional throughout the earlier phases of the project.
Design and installation verification (pathway #2 above) occurs throughout the project’s lifecycle by engaging an air barrier professional early in the project to collaborate with both the design and construction teams. This process involves review of the air barrier system(s) in the construction documents as well as periodic field inspections during construction. This pathway does not require quantitative air leakage testing, but rather aims to achieve air tightness by relying on the dedicated expertise of the verifier.
Regardless of the pathway chosen, verification must be performed by an independent third-party code official, registered design or engineering professional, or other approved agency. Building owners must receive a final commissioning report that includes all air barrier verification results and testing data. This documentation serves as verification for code officials and becomes part of the building’s permanent record.
YES, We Do Air Barrier Verification!
Copeland Building Envelope Consulting has a team of building science professionals who enjoy this stuff! We’d love to help seal the deal (we had to slip that one in) on your next project – contact us for air barrier verification services!
Join our growing tribe of building nerds and sign up for the best newsletter in AEC. Back of the Envelope delivers helpful info of immediate practical importance.