Bolthole Index

Washington County, Minnesota

Building permits, zoning and septic rules in Afton, Minnesota

The City of Afton, Minnesota requires a building permit, with fees paid before work starts, for building inside city limits1. Afton also runs its own zoning ordinance2. Septic permits for Afton addresses come from Washington County Public Health, not the city3. Dwellings need at least 800 square feet of main floor area4.

At a glance

Building permit
Required from the City of Afton before work starts1
Zoning
City of Afton administers its own zoning ordinance2
Septic
Permitted by Washington County Public Health3
Minimum dwelling size
800 sq ft main floor area (city quick guide)4
Short-term rentals
Only in the VHS-C zone, as a conditional accessory use in a commercial building5
Owner-builder
State licensing exemption for owners who build their own home6

Who to call

Building permits

City of Afton (City Hall, building permits and zoning)

Building permit applications and zoning for land inside Afton city limits

651-436-5090

3033 Saint Croix Trail

Septic permits

Washington County Public Health and Environment - Septic (SSTS)

Septic (SSTS) permits and inspections for every address in Washington County, including inside Afton

651-430-6655

[email protected]

Washington County Government Center, Room 4600, 14949 62nd Street North, Stillwater, MN 55082

Online permits →

Contact details are copied from each office’s official page and were checked against it on October 24, 2026.

Off-grid gear

Going off-grid in Afton means bringing your own water and power. The kit we’d start with:

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Do you need a building permit in Afton, Minnesota?

Yes. The City of Afton requires building permit applications to be submitted, reviewed and approved, with fees paid, before any work begins17. Construction, alteration and repair inside Afton follow the Minnesota State Building Code as the city has adopted it87.

Starting early is expensive: when a project begins before the required permit, conditional use permit or variance, the city triples the associated fees9. Applications can be sent by email to the city, and the city's own fee schedule sets the amounts; we could not confirm the building permit fee figures, so ask City Hall.

New homes also need a certificate of occupancy from the building official under state rules before anyone moves in10. Afton's own inspection schedule was not confirmed, so ask the building official which inspections apply.

Who issues building permits in Afton, and how do you reach them?

Inside Afton city limits, the City of Afton issues building permits, not Washington County117. Washington County's own page tells people to contact the city or township where the property sits to obtain a building permit.

City Hall takes building permit applications for the city7. The city also publishes a building official page, permit application forms and a fee schedule on aftonmn.gov under Permits and Licensing. Septic and driveway questions go elsewhere, as explained below.

Does Afton have zoning, and what does it mean for lot size, setbacks and RVs?

Afton administers its own zoning ordinance for land inside city limits2. The city's quick zoning guide names districts including A, AP, RR, VHS-R, VHS-C, I-1 and MS12. The guide cites chapter 12 while a 2024 amendment cites chapter 153, so confirm the current chapter with City Hall before you apply2.

The quick guide sets a minimum main floor area of 800 square feet for a dwelling4. Setbacks depend on the district: in districts A, AP and RR, accessory buildings over 1500 square feet need side and rear setbacks of 100 feet13. Sites in the St. Croix River overlay, the shoreland overlay or a floodplain follow separate, stricter setbacks13. Splitting land triggers subdivision rules and park dedication, by land or by fee14.

We could not confirm Afton's minimum lot sizes by district, or its rules for RVs, tiny homes, accessory dwellings or short-term stays beyond the one below. Short-term home rentals are allowed only in the VHS-C zone as a conditional accessory use in a commercial building5. For anything else, ask City Hall for the zoning map and the district rules for your parcel.

How do septic permits work inside Afton?

Washington County Public Health and Environment permits septic systems at Afton addresses, not the city315. Washington County requires a permit to install a new septic system, to repair or replace one, or to change or expand the building it serves16. The county's single-family installation permit is $8681715.

When a septic system must be upgraded, county approval comes before the city issues a building permit3. Residents connecting to the new city sewer system need proof of an approved county septic permit application and an active pipe-fitter license number before Afton issues its hookup permit18. The city does not state a mandatory connection rule, so ask City Hall whether your parcel must connect.

Washington County's soils are tough on drain fields: only 6.6% of county soils rate as not limited for a conventional system19. That means most lots need a site evaluation, and sometimes an engineered system.

Building a home in Afton: the steps, in order

  1. Ask Afton City Hall which zoning district your parcel is in and whether it sits in the St. Croix River, shoreland or floodplain overlay137.
  2. Apply to Washington County Public Health for a septic soil review and permit, or for city sewer, get county septic approval first315.
  3. If you plan to hook up to city sewer, submit the Afton hookup application with proof of the county septic application18.
  4. Submit the building permit application to the city and pay fees before any work starts1.
  5. Build to the Minnesota State Building Code and pass the inspections the building official sets20.
  6. Get a certificate of occupancy before you move in10.

Minnesota exempts owners who personally build their own home from residential contractor licensing, if they will live in it6. We could not confirm whether Afton adds its own owner-builder rules.

What stays with Washington County, and what to check before you buy

Septic permits stay with Washington County, as above3. Private wells are handled by the state: well construction generally requires a notification to the state before work starts21. We could not confirm any extra well rule inside Afton.

The county's rules for unincorporated land, such as its recreational vehicle prohibition, do not apply inside Afton; see the Washington County page for land outside the city.

Before you buy, check the floodplain: building a house or placing fill in a regulated floodplain needs a floodplain permit, and cities generally administer it within their own boundaries22. County-level numbers: Washington County's effective property tax rate is 1%23, and the median property tax bill is $4,012 a year24.

Watch-outs

  • Starting work before the required permit, conditional use permit or variance triples Afton's fees9.
  • Afton's zoning quick guide cites chapter 12 while a 2024 ordinance amendment cites chapter 153, so confirm the current chapter and your parcel's district with City Hall2.
  • We could not confirm Afton's rules for RVs, tiny homes, accessory dwellings, wells or minimum lot size by district; ask Afton City Hall7.

Sources

  1. Building Permit Information - City of Afton (Afton), quoted and re-checked
  2. City of Afton Quick Zoning Reference Guide (rev. 04-2024) (Afton), quoted and re-checked
  3. City of Afton Quick Zoning Reference Guide (rev. 04-2024) (Afton), quoted and re-checked
  4. City of Afton Quick Zoning Reference Guide (rev. 04-2024) (Afton), quoted and re-checked
  5. Summary Ordinance 14-2024, City of Afton (short term home rentals) (Afton), quoted and re-checked
  6. revisor.mn.gov (2026 county census)
  7. City of Afton (City Hall, building permits and zoning) (aftonmn.gov)
  8. Building Permit Information - City of Afton (Afton), quoted and re-checked
  9. City of Afton 2026 Administrative Permit Packet (Afton), quoted and re-checked
  10. Minnesota Administrative Rules, Part 1300.0220 — Certificate of Occupancy (Minnesota statewide rule), quoted and re-checked
  11. Building Permit Information - City of Afton (Afton), quoted and re-checked
  12. City of Afton Quick Zoning Reference Guide (rev. 04-2024) (Afton), quoted and re-checked
  13. City of Afton Quick Zoning Reference Guide (rev. 04-2024) (Afton), quoted and re-checked
  14. City of Afton Quick Zoning Reference Guide (rev. 04-2024) (Afton), quoted and re-checked
  15. Washington County Public Health and Environment - Septic (SSTS) (washingtoncountymn.gov)
  16. Subsurface Sewage Treatment Systems (SSTS), quoted and re-checked
  17. Subsurface Sewage Treatment Systems (SSTS), quoted and re-checked
  18. Septic Hook Up Application - City of Afton (Afton), quoted and re-checked
  19. Share of soils USDA rates "not limited" for a conventional septic drain field (SSURGO). A strict rating: the median county is about 6% and a tenth of counties are 0%, so a low figure means most lots need a site evaluation or an engineered system, not that septic is impossible. Cite it only with that caveat: Bolthole Index county data
  20. 1300.0210 INSPECTIONS (Minnesota statewide rule), quoted and re-checked
  21. 2025 Minnesota Statutes, section 103I.205: Well Construction (Minnesota statewide rule), quoted and re-checked
  22. Floodplain Regulations (Minnesota statewide rule), quoted and re-checked
  23. Effective property tax rate: Bolthole Index county data
  24. Median property tax bill: Bolthole Index county data

Written October 24, 2026 from the rules quoted below, each taken from an official source and re-checked by an independent reviewer. This is research, not legal advice: rules change, so confirm with the office before you buy or build.

Answers from the rulebook for Afton

Afton’s own rules

  • Building permitRequired

    Construction, reconstruction, alteration or repair of buildings inside Afton city limits

    • Permit must be obtained and fees paid before any work starts.
    • If work begins before the required permit, cup, or variance, the associated fees are tripled (per the building permit page).
    “building permit applications are required to be submitted to the city, the project reviewed and approved, and permit fees paid prior to commencing any work.”
  • Building code adoptedAdopted (with conditions)

    Construction, alteration and repair of buildings inside Afton city limits

    • Adoption is described by the city's building permit page; the adopting ordinance number and section were not located.
    “the state building code, as adopted by the city of afton, governs the construction, reconstruction, alteration, and repair of buildings and other structures to which the code is applicable.”
  • Local zoningPresent (with conditions)

    Land inside Afton city limits. The city administers its own zoning ordinance (chapter 153 per the 2024 amendment; the quick guide cites 'chapter 12, zoning').

    • The city's quick guide says there may be other requirements which may take precedence and that chapter 12 should be reviewed before applying.
    • Chapter numbering differs between sources (quick guide: chapter 12; ordinance 14-2024: chapter 153); the current codified chapter was not confirmed on the American Legal page, which was not readable beyond the overview.
    “an ordinance amending chapter 153 zoning of the city code, section 153.053 uses and section 153.115 short term home rentals”
  • Zoning districtsPartial

    Afton city zoning districts inside city limits

    • Districts named in the quick guide include A, AP, RR, VHS-R, VHS-C, I-1, and MS; the zoning map was linked but not opened.
    “minimum lot sizes * a ap rr rr rr vhs-r vhs-c i-1ab&c ms setback from city street”
  • Minimum dwelling sizeSpecified

    Dwellings inside Afton city limits (main floor area)

    • Figure is taken from the city's zoning quick guide (rev. 04-2024), which says to review chapter 12 before applying; the district-by-district ordinance figure was not confirmed.

    minimum main floor area: >= 800 sq ft

    “minimum dwelling size - main floor area: 800 square feet”
  • SetbacksDistrict specific (with conditions)

    Principal and accessory structures in districts A, AP and RR inside Afton city limits (district table in quick guide; accessory rule applies to A, AP and RR)

    • Structures in the St. Croix River overlay, shoreland overlay or floodplain must follow those separate ordinances' setbacks.
    • Setback from an 18% slope is governed by sec 12-132(a)(12) and 12-57(j) per the quick guide.
    • Substandard lots of 5 acres or less platted before March 3, 1970 have separate setbacks (see 12-132 e(5) and e(6) per the quick guide).
    • Setbacks from city streets and county roads vary by district (for example 105 ft and 150 ft from centerline in the quick guide table).

    side and rear setback for accessory buildings over 1500 sq ft: 100 ft (districts A, AP and RR)

    “for accessory buildings over 1500 square feet the side & rear setbacks are increased to 100 feet in a, ap and rr.”
  • Mandatory utility hookupConditional

    Residents hooking up to the new city sewer system inside Afton city limits

    • Hookup requires proof of an approved Washington County septic permit application and an active pipe-fitter license number.
    • The page does not state a mandatory-connection rule or distance-to-sewer threshold for new homes; not established.
    “before afton can issue a permit to a resident who is hooking up to the new city sewer system, we need confirmation/proof that the applicant has an approved septic permit application from washington county.”
  • Subdividing landRegulated (with conditions)

    Subdivision of land inside Afton city limits

    • Park dedication is required for subdivisions: the city chooses land dedication or a fee.
    • Park dedication fee is 7.5% of undeveloped land value, minimum $5,000 and maximum $10,000 per lot (per quick guide).
    • Minor, simple, and major subdivision applications exist on the city site (application packets), with fees by acreage; not opened in full.
    “park dedication requirements for subdivisions the city determines whether the park dedication requirements will be met by dedication of land or a fee.”
  • Short-term rentalsLimited

    Short-term home rentals inside Afton city limits

    • Allowed only in the VHS-C zone, as a conditional accessory use in a commercial building.
    • Ordinance 14-2024 adopted December 17, 2024; takes effect upon adoption and publication.
    “to allow short term home rentals only in the vhs-c zone as a conditional accessory use in a commercial building”
  • Permit feesPublished (with conditions)

    City land-use and administrative permits inside Afton city limits; building permit fee schedule is referenced but its amounts were not read

    • Administrative permit fee is $150 plus a $600 escrow (2026 packet); fee follows the city's adopted fee schedule.
    • If work starts before the required permit, cup, variance or other approval, associated fees are tripled (building permit page).

    administrative permit fee: 150 USD (plus $600 escrow)

    “city of afton administrative permit fee $150.00 + escrow $600.00”
  • Permit processPublished (with conditions)

    Building permits for work inside Afton city limits

    • Applications are submitted to the city, reviewed, approved, and fees paid before work starts.
    • Applications may be emailed to [email protected] (per city page search snippet; not quoted).
    “building permit applications are required to be submitted to the city, the project reviewed and approved, and permit fees paid prior to commencing any work.”

Rules another office applies inside Afton

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

  • Who permits septicCounty (with conditions)

    Septic (individual sewage treatment) systems on land inside Afton city limits, administered by Washington County Public Health

    • Septic systems in Afton are permitted through Washington County; the city issues sewer hookup permits only after county septic approval (see afton-utility-connection).
    • Schema geography for county authority is countywide; the county's authority is not limited to Afton, but the applicable rule here is the county's septic permit process inside Afton city.
    “septic systems required to be upgraded must be approved and a permit issued by washington county public health prior to issuance of a building permit or acceptance of a development agreement by the city.”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Afton or Washington County directly.

  • Owner-builder exemption — Owner-builder exemption from permit requirements inside Afton city limits
  • Inspections — Building inspections inside Afton city limits
  • Certificate of occupancy — Certificate of occupancy for new dwellings inside Afton city limits
  • Minimum lot size — Minimum lot size in Afton's main single-family residential district and agricultural/rural-residential district inside city limits
  • Lot coverage — Lot coverage / impervious surface limits inside Afton city limits
10 more unanswered
  • Building height
  • Living in an RV
  • Camping on your land
  • Tiny homes
  • Manufactured homes
  • Accessory dwellings
  • Septic inspection
  • Off-grid sanitation
  • Well permit
  • Agricultural exemption

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.

Unanswered questions are usually a sign that Afton publishes no rule on the point, not that none exists. Washington County’s page lists the county offices to call.

← All of Washington County: county rules, score and offices