Wisconsin Uniform Dwelling Code: What It Covers and Who Enforces It

What is the Wisconsin Uniform Dwelling Code?

The Uniform Dwelling Code (UDC) is the Wisconsin Department of Safety and Professional Services (DSPS) program identified as SPS 320 to 325. It governs one- and two-family dwelling units, including manufactured homes.^[6] If you want the full text, the DSPS UDC page and the Wisconsin Legislature's administrative code site carry the in-force rules, and both are free to read.

For a house or a duplex, the UDC is the code that applies.

A new one- or two-family dwelling needs a UDC permit.^[6]

Check the DSPS page for the current edition before you plan anything, because the code changes over time.

Which dwellings fall under the UDC

The UDC covers one- and two-family dwellings, including manufactured homes.^[6] That is the line to settle first.

A project can fall under different rules depending on whether it is a dwelling, an accessory structure or a commercial or multifamily building. Ask your local inspector whether the code applies to your dwelling type.

Ask the building inspector which rules apply to anything in the right-hand column. The inspector also handles questions about zoning, shoreland and floodplain limits, which are separate from the UDC.

Enforcement split between DSPS and delegated municipalities

DSPS administers the program, but permits and inspections generally run through the municipality when it has delegated UDC authority.^[6] Where that is the case, the permit application and the inspections both go through the local office.^[9]

In practice the chain looks like this:

1. DSPS administers the program.
2. The municipality with delegated authority issues the permit and conducts inspections.
3. You deal with the local inspector on plans, scheduling and documentation.

Required inspections for new dwellings include footings, foundation, rough construction, insulation and a final inspection.^[9]

Step by step

Required inspections for new dwellings

1. 1

   Footings

   Inspected before the foundation goes on.

2. 2

   Foundation

   Checked after the foundation is built.

3. 3

   Rough construction

   Inspected while the framing is exposed.

4. 4

   Insulation

   Checked before it is covered.

5. 5

   Final

   The last inspection of the finished dwelling.

Ask your inspector how each one is scheduled before you break ground.

Permit fees and application steps differ from one city to the next. The building permits by city table links to local pages, and city guides such as Madison and Green Bay cover the local details.

The city or the building inspector has the final word on what your project needs.

Most-encountered UDC rules for homeowners

Ask your contractor which code requirements apply to your job.

Footing depth: 48 inches

Footings and foundations, including those for landings and stoops, go below the frost penetration level or at least 48 inches below adjacent grade, whichever is deeper.^[1] The rule is SPS 321.16(1)(a), and it applies statewide. Wisconsin sets no county frost-depth table.^[1]

Footings may not be placed on frozen material.^[1]

Where bedrock sits less than 48 inches down, SPS 321.16(2)(c) lets a footing bear directly on it. The rock must be cleaned of all earth. Clay in crevices must be removed to the level of frost penetration or 1.5 times the crevice width (whichever is less). Provisions must also prevent water collecting along the foundation.^[1]

Forty-eight inches is the baseline, and a local inspector can ask for more.

Ask the building inspector before you excavate. The frost depth guide goes into the rule in more detail.

Roof snow load: Zone 1 and Zone 2

Roofs must be designed and constructed to support the minimum snow loads set by the Wisconsin snow-load zone map.^[7] Under SPS 321.02 and Figure 321.02, Zone 1 is 40 psf and Zone 2 is 30 psf, assigned by county.^[2] Zone 1 is the northern part of the state and Zone 2 the southern.

Side by side

Snow-load zones

Zone 1: 40 psf

• Northern part of the state
• Ashland, Marathon, Oneida, Vilas

vs

Zone 2: 30 psf

• Southern part of the state
• Dane, Milwaukee, Waukesha, La Crosse

Some examples from the code's county list:^[2]

• Zone 1 (40 psf): Ashland, Marathon, Oneida, Vilas
• Zone 2 (30 psf): Dane, Milwaukee, Waukesha, La Crosse

Twenty-one counties sit on the zone line, including Brown, Eau Claire, Outagamie, St. Croix and Winnebago. Jackson County is split by the line.

The code's figure is a scanned map, so ask the county or municipal building inspector which zone your lot is in.^[2] The full county list is on the snow load by county page.

This matters most when you buy plans, sheds or building kits designed for another state. Check the zone before you order.

If you are replacing a roof, the roofing guide covers how snow load fits with permits and licenses.

Certificates of financial responsibility for permit holders

A person who obtains a building permit for a one- or two-family dwelling holds a certificate of financial responsibility. That is either a Dwelling Contractor certification or a Dwelling Contractor Restricted certification.^[3] The authority is Wis. Stat. 101.654 and SPS 305.31.^[4]

The Dwelling Contractor credential requires a bond of at least $25,000 or general liability insurance of at least $250,000 per occurrence.^[3] The certificate is valid for one year.

It is a permit-pulling credential, not a trade license. It does not say which trades may work, only who may obtain the building permit.^[3]

Key takeaways

1. 01Permit holders need a Dwelling Contractor or Restricted certification
2. 02The credential needs a bond of at least $25,000 or liability insurance of at least $250,000 per occurrence
3. 03The certificate is valid for one year
4. 04It is not a trade license

The holder must also hold, or engage as an employee, a Dwelling Contractor Qualifier.^[5] Renewal takes 12 hours of department-approved continuing education, 4 of them on construction laws and codes, contracts, liability and risk management.^[5]

The owner-occupant exemption

An owner who lives or will live in the dwelling and applies for a permit to do work on it is exempt.^[4] When a municipality reports a new dwelling project to DSPS, the Dwelling Contractor and Qualifier information is required unless the submitter identifies the project as owner-occupied.^[8]

The exemption has conditions, so ask your inspector to confirm you qualify before you apply.

It also does not replace the trade-specific rules, so ask the city whether wiring or HVAC work needs its own permit.

If you hire a contractor, ask who is pulling the permit and confirm it with the issuing office yourself. Check the credential on the DSPS license lookup guide, and read the dwelling contractor license page for how the two credentials fit together. For a pro who holds these credentials, see the Wisconsin contractor directory.

Ask your city or inspector whether a permit is needed, since permits and code compliance are separate questions.

Confirm permit status with your city. Keep your approved plans, permit card and inspection records for resale or insurance questions.

Checked October 2026. Confirm the current code edition on the DSPS UDC page.

Quick answers

What does the Uniform Dwelling Code cover?

One- and two-family dwellings, including manufactured homes.

How deep must footings be?

Below the frost penetration level or at least 48 inches below adjacent grade, whichever is deeper.

Can an owner-occupant pull their own permit?

An owner who lives or will live in the dwelling is exempt from the contractor certification, but ask your inspector to confirm you qualify.