2026 Wisconsin Building Code Updates — What Contractors Need to Know
February 10, 2026
Wisconsin adopted the 2021 International Building Code (IBC) and 2021 International Residential Code (IRC) as the basis for its updated building codes, effective January 1, 2026. The Wisconsin Department of Safety and Professional Services (DSPS) approved the updates in September 2025 after a 24-month review cycle. These are the first comprehensive code updates since 2018.
Key Changes to the Commercial Building Code (SPS 362)
The updated SPS 362 aligns Wisconsin with the 2021 IBC while retaining several state-specific amendments. The most notable changes affect fire-resistance requirements for Type V-A construction above 4 stories, which now require 2-hour rated floor assemblies (up from 1-hour). Mass timber construction is now explicitly permitted under a new Type IV-C classification, opening the door for taller wood-frame commercial buildings. Accessibility requirements have been updated to match the 2018 ADA Standards, which expand maneuvering clearance requirements at doors and adds new requirements for multi-stall restrooms in commercial occupancies.
Residential Code Changes (SPS 321–325)
For residential construction, the most impactful change is the adoption of updated energy requirements under SPS 363 (see our separate guide on energy code changes). Beyond energy, the updated residential code requires arc-fault circuit interrupter (AFCI) protection in all habitable rooms (previously limited to bedrooms and living areas). Stair geometry requirements now allow 7.75-inch maximum riser height (down from 8.25 inches) and 10-inch minimum tread depth (up from 9 inches). Egress window requirements have been standardized across all municipalities — a change that eliminates several local amendments that previously created confusion for contractors working across jurisdictions.
Changes to Plan Review and Inspection
Milwaukee, Madison, and Green Bay have all implemented new digital plan submission requirements as part of the code update. Paper plan sets are still accepted but now carry a $75–$150 surcharge in these three cities. Digital submissions must use PDF/A format at minimum 200 DPI with searchable text layers. DSPS has also updated its commercial plan review process: projects valued over $500,000 now require a pre-application conference, and plan review timelines have been formalized at 15 business days for the initial review (20 business days for projects over $5 million).
Compliance Timeline
Projects with complete permit applications submitted before January 1, 2026 may be constructed under the previous code. All new applications after January 1 must comply with the updated code. DSPS has issued a 6-month grace period (through June 30, 2026) during which inspectors will issue warnings rather than stop-work orders for minor violations of newly adopted provisions — but only where the previous code was met. This grace period does not apply to life-safety provisions (fire-resistance, egress, structural).
How This Affects Permit Fees
The code update itself does not change permit fees, but several municipalities have used the transition as an opportunity to update their fee schedules simultaneously. Milwaukee increased commercial building permit fees by 12% effective March 2026. Madison adjusted its plan review fee formula from 65% of the permit fee to 70%. Smaller municipalities like Waukesha, Oshkosh, and Appleton have not yet announced fee changes. Use our Fee Calculator to check current fees for your specific jurisdiction and project type.
Data note: The permit data referenced in this article was verified against official municipal sources as of February 2026. Fee schedules and requirements can change at any time. Always confirm current requirements directly with your local permit office before submitting applications. Use our Fee Calculator to get the latest fee estimates for your specific jurisdiction and project type.
Frequently asked questions
When do the 2026 Wisconsin building code changes take effect?
The updated building codes took effect January 1, 2026. Projects with complete permit applications submitted before that date may be constructed under the previous code. DSPS has issued a 6-month grace period through June 30, 2026 for minor violations of newly adopted provisions.
What are the biggest changes in the 2026 Wisconsin building code?
The biggest changes include: adoption of the 2021 IBC and IRC as base codes, new mass timber construction allowances (Type IV-C), updated fire-resistance requirements for Type V-A buildings above 4 stories, AFCI protection required in all habitable rooms, updated stair geometry requirements, and new digital plan submission requirements in Milwaukee, Madison, and Green Bay.
Are there new energy code requirements in the 2026 Wisconsin update?
Yes. Wisconsin adopted updated energy requirements under SPS 363 as part of the 2026 code cycle. Key changes include higher insulation R-values, updated HVAC efficiency minimums, and new air sealing verification requirements. See our full guide on Wisconsin energy code requirements for details.
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