An Architects Perspective: What I Love about Wisconsin’s New Building Code

In the wake of the State of Wisconsin’s update to the Commercial Building Code, and its associated referenced standards, much has been written and discussed regarding the impacts to the building industry at large. Building owners, developers, facilities managers, contractors, communities, code officials, architects and engineers are all navigating the intricacies of the updates and as with any shift in regulation, feeling the associated aches and pains. From special inspections to enlarged accessible clearances to heightened energy efficiency requirements, the built environment is continuing to evolve, and the economic impact is real and always a valid concern. But, building codes are…. A good thing! Codes are generally the result of our collective experience in avoiding loss of life, property and resources. They convey a level of trust to the public that the built environment they’re experiencing supports their Health, Safety and Welfare.

As an Architect, there are some innovative provisions in the new building code that allow the design community greater flexibility that did not exist in previous editions. Here are my Top 10:

1. Mass Timber

Mass Timber structures have been making a huge impact as a practical and safe structural system for several years. Its robustness and resilience to fire merely add to the inherent warmth and beauty of exposed wood columns beams, floors and ceiling systems. IBC Chapter 602 (and Construction Type IV) has been substantially expanded to include design criteria for Mass Timber

2. Atriums

Atriums get a streamlined definition in 202 and greater design flexibility in 404.5 and 404.6. Thus, it is now possible to connect more than 2 stories WITHOUT the need for smoke control and enclosure IF other means of protection are provided to openings beyond the lower 2 stories. This is due to the acknowledgment of more advanced separation and open protections systems.

3. Accessory Storage Spaces

311.1.1 has removed the limit of 100 square for Storage spaces if the storage is accessory to the primary occupancy. This reduces cost of separations for compartmentalized and separated storage.

4. Occupant Load for Business Use

On Table 1004.5, the gross area factor has been increased from 100 to 150 square feet per occupant which more accurately represents workspace size and densities in the post covid office space. This can slightly reduce the overall occupant load and quantities of minimum required plumbing fixtures.

5. Egress from Mechanical Rooms and Penthouses

In 1006.2.1, the common path of travel need not apply to spaces of this nature. These are generally difficult to add a second exit to as large building equipment can restrict and elongate egress paths. As these spaces are not open to public, this is a practical concession.

6. Locks and Latches for exterior spaces

Exterior spaces like courtyards or balconies often require egress back through the interior of the building they are accessed from. These present a conflict between security and life safety which were either left unsecured or involved lengthy negotiations and/or variances to arrive at an agreeable solution. IBC 1010.2.4, now provides conditions by which these spaces may be secured via locks when the 6 stated conditions are met.

7. New Climate Map

On the IECC C301 “Climate Map”, Wisconsin moves climate zones 6A (Southern counties) and 7 (Northern counties) to 5A and 6A respectively.

8. Additional allowances for combustible materials in Types I and II construction

603.1 “Wood nailers for parapet flashing and roof cants” have been to the list of Allowable Materials. This provides greater clarity in practical attachments for roof construction.

9. Wisconsin Amendment for Fire Wall Horizontal Continuity

SPS 362.0706(2) provides an additional compliance for horizontal firewall continuity by extending the required rating 4 feet in one direction.

10. Fire Resistive Wall Ratings for Exterior Walls

This portion of Table 601 has been moved to 705.5 to coordinate better to adjacent references.

Bibliography

International Code Council. (2021). International Building Code (IBC).

International Code Council. (2021). International Existing Building Code (IEBC).

International Code Council. (2021). International Energy Conservation Code (IECC).

International Code Council. (2021). ICC Performance Code for Buildings and Facilities.

International Code Council. (2021). International Building Code (IBC): Ch. 2, 3, 4, 6, 7, 10.

International Code Council. (2021). International Energy Conservation Code (IECC): Ch. C3 Climate Zones.

Wisconsin Department of Safety and Professional Services. (2025). Wisconsin Commercial Building Code, SPS 361–366.

American Wood Council. (2021). Technical Provisions for Mass Timber Construction.

Thornburg, D. W. (2021). 2021 International Building Code Illustrated Handbook. McGraw-Hill Education.

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