In Wisconsin, new commercial buildings and additions built after November 1st, 2025 (and projects submitting plans after October 1, 2025) now require whole-building commercial blower door testing as an option for compliance. Wisconsin recently adopted the 2021 International Energy Conservation Code (IECC) with state-specific modifications, as well as ASHRAE 90.1-2019. Whole-building blower door testing is now used to verify building envelope air leakage.
Commercial blower door testing is primarily mandated for occupancies where the project relies on air-leakage compliance paths or when the local municipality is enforcing added rules. For blower door testing, the building envelope is typically considered acceptable if the air leakage rate test returns less than 0.40 cubic feet per minute (cfm) per square foot of building envelope (commonly written as: cfm/sq ft BE) at a pressure differential of 75 pascals (Pa) (this equals 0.3 inches of water column (WC)).
Do All New Buildings Require a Commercial Blower Door Test in Wisconsin?
While earlier versions of the state of Wisconsin commercial building code relied primarily on visual inspections of air barriers, code updates and modern versions (such as the recently adopted 2021 IECC and ASHRAE 90.1) have shifted more to ensuring and documenting inspections of a continuous air barrier or completing a commercial blower door test for most occupancies. Testing must generally conform to ASTM E779 or equivalent standards. The tested air leakage typically cannot exceed 0.40 cfm/sq ft BE.
However, not all new WI commercial buildings and additions must be tested. There are a few exceptions. You may be exempt from testing under the following conditions:
- For multi-family residential projects, compartmentalization testing (testing individual units) is often allowed as an alternative to whole-building testing. However, blower door testing is still required (whether performed in sections or as a whole-building test).
- Certain agricultural buildings, unconditioned spaces, and smaller structures may be exempt.
- Depending on the local jurisdiction’s exact adoption of the code, you can sometimes opt for the visual verification method over whole-building blower door testing.
When to Perform a Commercial Blower Door Test During Construction
The new WI energy code states that testing must occur after the air barrier rough-in and after all penetrations (such as utilities, plumbing, electrical, and ventilation) are installed. This new WI code applies to most new commercial, industrial, and multi-family residential buildings.
You can review the exact testing methodologies and acceptable air leakage rates directly in the Wisconsin Legislature Chapter SPS 322 rules or consult the complete code architecture on the Wisconsin DSPS Commercial Buildings portal. Building codes in Wisconsin are enforced at both the state level by the Department of Safety and Professional Services (DSPS) and locally by municipal inspectors. Because municipalities adopt code versions on different timelines, always verify exactly which edition is active in your local area by contacting your local Wisconsin DSPS field office.
How to Schedule Commercial Blower Door Testing in Wisconsin
Commercial blower door testing can be performed by certified and independent building envelope consultants in Wisconsin. Using their building science expertise and specialized equipment, they come to your jobsite after the air barrier is roughed-in and complete your required testing.
Accurate-Airtight Enclosures has been trusted by commercial building owners in Madison since 1998, and we are highly knowledgeable and trained on the new Wisconsin commercial building codes.
Our commercial air barrier testing services will ensure that your building is energy efficient, comfortable for occupants, and, most importantly, code-compliant.
