Zoning, building permits and septic rules in Ontwa Township, Michigan

Ontwa Township’s own rules

• Certificate of occupancyRequired

  Use or occupancy of buildings and structures inside Ontwa township

  • Exception: 'except as otherwise provided in the building code'.
  • A temporary certificate may be issued for part of a building before the whole is complete.
  • The certificate is issued by the building official.

  “no building or structure, except as otherwise provided in the building code, shall be used or occupied, and no change in the use of a building or portion thereof shall be made until the building official has issued a certificate of occupancy.”

• Local zoningPresent

  Land inside Ontwa township, Cass County, Michigan

  • The township page lists a zoning ordinance amended January 12, 2026 (effective 2-1-2026); the text reviewed here is the version amended through November 7, 2024.

  “zoning ordinance amended january 12, 2026 - effective 2-1-2026 the amended zoning ordinance covers the following documents.”

• Zoning districtsPublished

  Zoning districts in Ontwa township

  • Districts per the table of contents: AR, R-1A, R-1, L-R, R-2, M-H, MFR, C-1, C-2, I-1, I-2, plus PUD.
  • A zoning map as of 2/1/2026 is listed on the township ordinances page.

  “article v - agricultural/residential district "ar" 5.01 - 5.05 v-1 article vi - residential district "r-1a" 6.01 - 6.05 vi-1 article vii - residential district "r-1" 7.01 - 7.05 vii-1 article viii - lake residential district "l-r" 8.01 - 8.05 viii-1 article ix - residential district "r-2" 9.01 - 9.05 ix-1 article x - manufactured home park district "m-h" 10.01 - 10.02 x-1 article xa - multi family residential district "mfr" 10a.01 - 10a.06 xa-1 article xi - commercial/service district "c-1" 11.01 - 11.06 xi-1 article xia - general commercial district "c-2" 11a.01 - 11a.06 xia-1”

• Minimum dwelling sizeSpecified

  Residential R-1 district, single-family residences, Ontwa township

  • Multi-story dwellings need a ground floor of at least 700 sq ft.
  • The required garage must be at least 300 sq ft.

  minimum floor area: >= 1200 sq ft (multi-story: 700 sq ft ground floor)

  “(f) floor area - for single family residences, there shall be a minimum floor area of one thousand two hundred (1,200) square feet. dwellings having more than one story shall have a ground floor area of at least seven hundred (700) square feet. the required garage shall have a minimum floor area of three hundred (300) square feet.”

  2 more reviewed findings on this topic

  • Specified — Agricultural/Residential (AR) district, Ontwa township

    “(f) floor area - there shall be a minimum floor area of one thousand (1,000) square feet. dwellings having more than one story shall have a ground floor area of at least eight hundred (800) square feet.”

  • Specified — Residential R-1A district, single-family dwellings, Ontwa township

    “(f) floor area - for single family dwellings, there shall be a minimum floor area of one thousand five hundred (1,500) square feet. dwellings having more than one story shall have a ground floor area of at least eight hundred (800) square feet. the required attached garage shall have a minimum floor area of three hundred (300) square feet.”

• Minimum lot sizeSpecified

  Agricultural/Residential (AR) district, Ontwa township

  • A reduced lot area (a figure of 48,000 sq ft appears) applies where public sewer service is installed and the home is connected to the sewer; that proviso was not quoted in full.
  • Minimum lot width at the front setback line is 200 feet.

  minimum lot area: >= 60000 sq ft (reduced with public sewer)

  “(d) lot area - there shall be a lot area of at least sixty thousand (60,000) square feet; provided that where a public sewer service is installed, the lot area may be reduced to forty-eight”

• SetbacksSpecified

  Agricultural/Residential (AR) district, Ontwa township

  • Side yard is 30 feet where a side lot line adjoins a street.

  front yard: >= 35 feet · each side yard: >= 25 feet (30 ft on street side) · rear yard: >= 30 feet

  “(a) front yard - there shall be a front yard of no less than thirty-five (35) feet. (b) side yard - there shall be two side yards. no side yard shall be less than twenty-five (25) feet; provided, however, that when a side lot line adjoins a street, a minimum yard of thirty (30) feet is required. (amended 6/13/16) (c) rear yard - there shall be a rear yard of at least thirty (30) feet.”

• Lot coverageSpecified

  Residential R-1A district, Ontwa township

  • The zoning administrator may require a storm-water mitigation plan by a Michigan licensed professional engineer.
  • AR district coverage limit not read.

  maximum coverage by buildings and impervious surfaces: <= 35 percent of parcel

  “no more than thirty-five percent (35%) of the total area of a parcel of land shall be covered with buildings, structures or other impervious surfaces. a storm-water mitigation plan designed by a michigan licensed, professional engineer, may be required by the zoning administrator.”

• Building heightSpecified

  Agricultural/Residential (AR) district, Ontwa township

  • Whichever is less: 35 feet or 2 1/2 stories.
  • Other buildings and structures may not exceed their usual and customary heights.
  • Height exceptions are in section 3.07.

  maximum height: <= 35 feet (or 2.5 stories, whichever is less)

  “section 5.03. height regulations. no building or structure shall exceed thirty-five (35) feet in height or two and one half (2 1/2) stories whichever is less; all other buildings and structures shall not exceed their usual and customary heights. (amended 8/14/17)”

• Mandatory utility hookupConditional

  New buildings needing sewage disposal inside Ontwa township

  • Sewer connection is required only if any point of the principal building is within 300 feet of a public sanitary sewer service.
  • The same section requires a safe and sanitary water supply under Cass County, Michigan and federal requirements; no public-water connection distance rule was seen.
  • Section amended 12/10/18.

  sewer connection distance: <= 300 feet

  “for new buildings, structures, and/or uses where sewage disposal is required, connection to a public sanitary sewer service is required if any point of the principal building is within 300 feet of a public sanitary sewer service.”

• Subdividing landRegulated (with conditions)

  Subdivisions and site condominiums inside Ontwa township

  • Separate Subdivision Ordinance 11-96-1, Site Condominium Ordinance 11-96-2, Private Road Ordinance 11-96-3 and Land Division Ordinance 10-97 apply; only their titles were confirmed.

  “private road ordinance no. 11-96-3 subdivision ordinance no. 11-96-1 (amended june 12, 2023) site condominium ordinance no. 11-96-2 (amended june 12, 2023) land division ordinance no. 10-97”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Ontwa Township or Cass County directly.

• Building permit — Building permits inside Ontwa township
• Owner-builder exemption — Owner-builder permits inside Ontwa township
• Building code adopted — Building code inside Ontwa township
• Inspections — Building inspections inside Ontwa township
• Living in an RV — RV occupancy inside Ontwa township

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.