WI Solar/Wind Contractor Licensing

City of Madison - Contractor Licensing

AI summary · 7/12/2026

If you're installing a solar thermal system on your own owner-occupied home in Madison, you can do the work yourself without a contractor license. For hired installations, your contractor must hold either a Class A-4 license from the City or be certified as a solar thermal installer by the North American Board of Certified Energy Practitioners (NABCEP).

To install active solar heating equipment in Madison, you must obtain a Class A-4 license from the City or hold current NABCEP solar thermal installer certification (accepted since 2008 as an alternative). Your installations must meet Madison's equipment standards covering collector orientation, system configuration, piping, insulation, storage, sensors, and monitoring requirements.

Madison's Class A-4 licensing requirement for solar thermal installers is codified in the City's Heating, Ventilating and Air Conditioning Code (Madison Code § 30.05) and applies to anyone installing, altering, or repairing active solar heating systems. The 2008 amendment (Ordinance 08-00122) created an equivalency allowing NABCEP-certified installers to work without the local Class A-4 license, reducing local regulatory burden while maintaining standards. Single-family owner-occupants are exempt from licensing requirements.

Program details

Program ID
406
Last updated
12/17/2024

Eligibility

Sectors
installers/contractors
Technologies
solar water heat solar space heat

Program summary

Although the State of Wisconsin does not have any specific laws for contractors dealing with renewable energy, the City of Madison has issued rules for contractor licensing and equipment standards for solar thermal installations. In the City’s Heating, Ventilating and Air Conditioning Code is a requirement for a Class A-4 license for "a person desiring to enter into the business of installing, altering or repairing active solar heating equipment" as well as fee and examination details. As a result of a 2008 amendment (Ordinance No. 08-00122), the A-4 certification is not required if the contractor is certified as a solar thermal installer by the North American Board of Certified Energy Practitioners (NABCEP). In addition, the MadiSUN program web site notes that single-family homeowners installing systems on their own owner-occupied homes may perform the work themselves and do not require the otherwise applicable licenses.

Installation standards for solar thermal equipment cover subjects such as orientation of the collector, system configuration, material degradation, sensors, piping and insulation, fluids, storage, monitoring and manuals. The 2008 legislation made certain changes to these standards in order to bring them up to date with current technology and practices (Madison Code of Ordinances § 30.05).

Contact & resources

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