Uniform Dwelling Code – Frequently Asked Questions

Building a UDC Compliant Home

The statewide code for newer homes in Wisconsin is the Uniform Dwelling Code(UDC), Chs. SPS 320-325 of the Wisconsin Administrative Code and its adopted references. It is a uniform building code that replaces numerous local or non-existent building codes for new homes. Municipalities may not adopt a more or less stringent code. The UDC was developed and is updated with input from a citizens’ Dwelling Code Council.

The UDC is principally enforced by municipal building inspection departments. The Wisconsin Division of Safety and Buildings facilitates uniformity of its enforcement through code development, code interpretations, special investigations, inspector training and certification, processing of petitions for variance and monitoring manufactured dwelling firms.


Q: What is the purpose of the UDC?

A. The UDC is a uniform statewide code that sets minimum standards for fire safety; structural strength; energy conservation; erosion control; heating, plumbing and electrical systems; and general health and safety in new dwellings.

Q: What determines the cost of a building permit?

A. The value of a project determines the cost of a permit. Municipalities vary. Contact Brian Wert. When figuring the value of new home construction, the value is everything but the cost of the land.

Q: What buildings are covered by the UDC?

A. Basically it covers new one and two-family dwellings built since June 1, 1980 and their additions and alterations.

This includes:

    • Seasonal and recreational dwellings (Electrical, heating or plumbing systems are not required, but if installed they shall comply with the applicable codes. If a home is heated, then it shall be insulated. Local sanitary requirements may require certain plumbing systems.)
    • One- and two-family condominium buildings.
    • A single-family residence connected to a commercial occupancy.
    • Community-based residential facilities with up to 8 residents.
    • Manufactured, modular or panelized dwellings regulated by the State (but not mobile or manufactured homes regulated by the Federal Government).
    • Additions to mobile or manufactured homes produced after June 1, 1980.
  • A non-residential building, such as a barn, that is converted to a dwelling.

Q: What structures are not covered by the UDC?

A. The following are not covered:

    • Dwellings built before June 1, 1980 or additions and alterations to such dwellings.
    • Mobile (manufactured) homes which are instead subject to Federal standards.
    • Multi-unit (three or more) residential buildings which are regulated by the State Commercial Building Codes.
  • Detached garages or accessory buildings.

Q: What about homes built before June 1, 1980?

A. The State does not have a construction or heating code for older homes or any accessory structures or outbuildings. However, the State Plumbing and Electrical Codes and smoke detector codes do apply to all dwellings, regardless of age.

For construction and heating standards for older homes, municipalities may adopt any or no code. Many use the UDC. Others use the Wisconsin Uniform Building Code, which is not a State code but rather a regional code in southeastern Wisconsin.

Q: How is the UDC enforced?

A. The UDC is principally enforced by municipal or county building inspectors who must be state-certified. They check for code compliance while construction is open for inspection. Municipalities of less than 2,500 population have the option of whether or not to enforce the code or to have the state provide enforcement. To determine if there is state enforcement, contact the Division of Safety and Buildings (address at end of brochure). In any case, state statutes require compliance with the UDC rules by owners and builders, even where there is no local enforcement.

Q:What are the typical steps in building, adding onto or altering a code-complying home?

A. The steps to be taken by an owner or builder can be summarized as follows. (Some steps may not apply to alterations or additions):

    • Make initial contact with local zoning and building inspection departments to get an Energy Worksheet, Building Permit Application, zoning rules and other basic information. Determine if your alteration requires a permit or if you need your property surveyed.
    • Design the home using standard design tables from the UDC or design a more customized home as long as it is demonstrated that the design meets the general engineering standards of the code. In addition to the UDC, the dwelling’s design may also be subject to subdivision rules or restrictive covenants.
    • Obtain sanitary or well permits from the county or municipality if the home will use a private sewage system or well.
    • Obtain floodplain, zoning and land use approvals from the county and municipality having authority.
    • Obtain driveway or other local permits.
    • Obtain any necessary utility approvals.
    • Submit complete plans including plot, erosion control, foundation, floor layout(s), building cross- section(s) and exterior building wall views (elevations); Energy Worksheet; Permit Application; fees and copies of the above permits to the municipal inspection department.
    • Begin construction after plans are approved and building permit is issued and posted.
    • Call for inspections of each phase of construction at least 2 business days prior to when work is to be covered up (check the local inspector’s instructions). Inspectors will check for compliance with the code. Cosmetic or non-code workmanship items will not normally be ordered corrected. However, inspectors may also check that the approved plans are being followed, including items above the code minimums. Deviations from the original plans may require submittal of revised plans.
    • Take occupancy after receiving a final inspection in which no health or safety violations are found. (Some municipalities will issue occupancy permits.) Also, the dwelling’s exterior must be completed within two years after permit issuance.
  • Correct any other code non-compliances, including stabilization by vegetation of any exposed soil.

Q: Who may do the work?

A. Following is a summary of applicable regulations:

    • Anyone may design the home, other than for homes in a floodplain.
    • The construction and erosion control permits must be taken out by a state-certified contractor or by the owner who occupies the home currently or after completion. Note that State UDC Contractor certification checks for general liability insurance only – it does not test the technical competency of the builder.
    • The plumbing work must be supervised by a master plumber and installed by licensed plumbers. (Only after the dwelling is occupied, may an owner install additional plumbing beyond the pre-requisite kitchen sink and full bathroom, unless prohibited by municipal ordinance.)
    • All heating contractors must be state-registered. Owners working on their own property are exempted.
    • Municipalities may have additional licensing requirements as well as bonding or insurance requirements.
    • In any case, we suggest that you:
    • Check your contractors for proper liability and worker’s compensation insurance to minimize your liability for injuries and damages to, or caused by, contractors.
    • Check past customer references.
    • Have a written contract.
  • Obtain lien waivers from your subcontractors, so you are not financially responsible if your general contractor fails to pay them.

Q: What could happen if the code is not followed?

A. Failure to comply with the code could cause the following:

    • Endangering the health and safety of self, family or guests.
    • Levying of fines and/or refusal to grant occupancy permit by local building inspection department.
    • Civil action by owners against builders.
    • Difficulty in selling the home.
    • Civil action by future owners or tenants against original owners or builders. (The average home is resold every 5 to 7 years.)
    • Difficulty in obtaining mortgage loans or property insurance.
  • Loss of building and community values.

Q: What if I am not able to exactly follow the Code?

A. If it would be difficult to comply with a particular code provision because of special site or design considerations, then you may submit a petition for variance with the required fees to the State. Your variance must show an equivalence to the code provision by different means. (Forms are available from your local building inspector or the Safety and Buildings Division.)

Q: What If I have a problem with my home?

A. Every situation is different, but possible actions include:

    • Contact the responsible general contractor and/or subcontractor for resolution.
    • Contact your homeowner’s warranty program, if applicable.
    • Contact the local building inspector if the problems are code-related. (Note that orders may be written against you as the owner.)
    • Use the local homebuilder association’s arbitration services, if applicable.
    • Obtain a consulting engineer or private building inspector’s report.
    • Contact the Wisconsin Department of Agriculture, Trade and Consumer Protection (1-800-422-7128) for alteration and addition problems.
    • Use the small claims court system.
    • Contact an independent mediation/arbitration service.
  • Obtain a lawyer.