Zoning, building permits and septic rules in Town of Cottage Grove, Wisconsin

Town of Cottage Grove’s own rules

• Building permitRequired

  New homes, duplexes and 4-unit buildings, alterations, additions, decks, garages, sheds, pools, demolition and commercial work inside Cottage Grove town

  • Permit must be applied for and paid before the permit is issued; construction may proceed only after the permit is issued.
  • Additions, decks, porches, garages or changes to footprint or volume first require a Dane County zoning permit before the town building permit.
  • Permits are required even if the owner does the work personally.

  “permits are required even if you are doing the work yourself.”

• Owner-builder exemptionNot available

  Owners who do their own construction work inside Cottage Grove town

  • The page's statement is about permit requirements for owner-performed work; it does not quote a separate owner-builder exemption section.

  “permits are required even if you are doing the work yourself.”

• Building code adoptedAdopted

  Buildings inside Cottage Grove town under the town's Chapter 12 building code (Uniform Building Code)

  • The current codified text of Chapter 12 was not opened. The adoption history shows the 2024 amendment and the 2019 codification of Chapters 12 through 25 by Ordinance 2019-02.
  • A 2009 amending ordinance text (adopting Commerce COMM 20-25 Uniform Dwelling Code and related codes) appeared only in a search snippet; its PDF returned HTTP 404 and it is not relied on here.

  “ordinance 2024-05-20b amending chapter 12 of the town code of ordinances – uniform building code”

• Subdividing landRegulated (with conditions)

  Division of land into lots inside Cottage Grove town under the town's Chapter 15 land division and planning code

  • The town's adoption history lists Chapter 15 amendments, including one dated October 10, 2025 with ordinance number 2025-10-06 (the date and number on the page do not match exactly).
  • The Chapter 15 text itself was not opened, so lot-size and survey rules are not stated here.

  “october 10, 2025 ordinance 2025-10-06 amending chapter 15 - land division and planning code”

• Permit processPublished (with conditions)

  Building permit application and issuance in Cottage Grove town

  • Apply to the town building inspector before the planned start date; the permit is not issued until paid.
  • Pick up and pay at Town Hall weekdays 8:00 am to 12:30 pm (closed Fridays between Memorial Day and Labor Day), mail a check to 4058 County Road N, or pay online.
  • Online card payments carry a convenience fee; the office emails or mails permits not paid in person.
  • Commercial construction also needs a petition for change of land use and a design review checklist; design review is under section 12.08 of Chapter 12.

  processing time for general applications: 3-5 days (general applications; other application types not stated) · online payment convenience fee: 2.95 percent ($3.99 minimum applies)

  “once applied for, allow 3-5 days for general applications to be processed.”

Rules another office applies inside Town of Cottage Grove

Town of Cottage Grove does not set these itself; the county, a health district or the state does, and they apply to every address inside its limits.

• Septic permitRequired

  New or modified private onsite wastewater treatment systems (POWTS) inside Cottage Grove town, under the Wisconsin statewide rule

  • Applies through the local governmental unit where the system is located; the state statute (s. 145.20(2)(b)) makes that unit responsible for approving sanitary permits.
  • Permit is valid for 2 years from issuance unless renewed (SPS 383.21(5)).
  • The local unit may require extra information or a fee by ordinance (SPS 383.21(2)(c)6 and 7).

  “the application for a sanitary permit shall be submitted to the appropriate governmental unit where the powts is located or will be located.”

• Septic inspectionRequired

  POWTS installations or modifications inside Cottage Grove town, under the Wisconsin statewide rule

  • The final inspection is the one set out in SPS 383.26, which was not opened.
  • The permit must stay posted until installation is complete and a final inspection opportunity occurs.

  “the sanitary permit shall be posted until a powts installation or modification is completed and an opportunity for a final inspection occurs in accordance with s. sps 383.26.”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Town of Cottage Grove or Dane County directly.

• Inspections — Building inspections for work inside Cottage Grove town
• Certificate of occupancy — Certificates of occupancy for new dwellings inside Cottage Grove town
• Local zoning — Whether Cottage Grove town adopts and administers its own zoning ordinance for land inside the town
• Zoning districts — Zoning districts mapped for land inside Cottage Grove town
• Minimum dwelling size — Minimum dwelling floor area inside Cottage Grove town

Each answer was extracted from an official source and independently re-checked against that source by a second reviewer. That is an evidence check, not legal advice. Rules change; confirm with the authority before you buy or build.