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

Casco Township’s own rules

• Building permitRequired

  Barns, homes, garages, additions, decks and ponds inside Casco township

  • The page lists typical permits for barns, homes, garages, additions, decks and ponds; pools over 24 inches deep require permits.
  • Site plan approval is required before a building permit is issued (zoning page).
  • Mechanical, electrical and plumbing permits may be needed in addition to the building permit.

  “casco township is a zoned community requiring building permits.”

• InspectionsRequired

  Buildings inside Casco township under township building permits

  • Inspections are scheduled per instructions printed on each permit; a re-inspection fee applies if the site is not ready when the inspection is requested.

  “our building inspectors are required to inspect buildings to meet the state code and enforce the guidelines set forth in the code.”

• Local zoningPresent (with conditions)

  Land inside Casco township (St. Clair County, MI) limits. Casco township administers its own zoning ordinance (Chapter 64 of its Code of Ordinances).

  • The zoning page says site plan approval is required before any building permit can be issued and that the zoning administrator handles residential site plan reviews.
  • The zoning page links a 'zoning ordinance (2026)'. This record relies on the 04-17-24 PDF that was opened; the 2026 version was not opened and may supersede it.

  “casco township is a zoned community requiring permits for development.”

• Zoning districtsPublished (with conditions)

  Zoning districts established for land inside Casco township

  • Districts include AG (agricultural), R-1 (rural residential), R-2 (suburban residential), RT (manufactured home residential), B-1, B-2, ROS, IND and OS.
  • The district map was linked from the zoning page but not opened.

  “article 5 – r-1, rural residential district”

• Minimum dwelling sizeDistrict specific (with conditions)

  Single-family and two-family dwellings inside Casco township, by number of bedrooms and stories; the ordinance also lists per-district first-floor and total minimums (AG, R-1/R-2, RT)

  • Basements, breezeways, porches and attached garages are excluded from floor area for multiple-family developments (footnote e).
  • Per-district first-floor and total figures apply by story count (AG: 1000 one-story; R-1/R-2: 750 one-story; RT: 720 one-story).
  • Multiple-family developments have separate minimums (efficiency 350 sq ft to four-bedroom 1,150 sq ft).

  minimum floor area per unit, one bedroom: >= 750 square feet (all districts, single and two-family dwellings) · minimum floor area per unit, two bedroom: >= 870 square feet (all districts, single and two-family dwellings) · minimum floor area per unit, three bedroom: >= 1000 square feet (all districts, single and two-family dwellings) · minimum floor area per unit, four bedroom: >= 1200 square feet (all districts, single and two-family dwellings) · additional floor area per bedroom beyond four: per 120 square feet (all districts, single and two-family dwellings)

  “the minimum required floor area per dwelling unit for single and two-family dwellings shall be determined by the number of bedrooms and the number ofstories of the dwelling unit”

• Minimum lot sizeDistrict specific (with conditions)

  Agricultural (AG) district lots inside Casco township (main farm/rural district)

  • Footnote (f): where sewer systems are provided, the minimum lot area and width may be reduced by twenty (20) percent.
  • Footnote (j) referenced in the table was not read.
  • Figures are from OCR-extracted text of Section 59 and should be verified against the PDF table.

  minimum lot area: >= 5 acres · minimum lot width: >= 200 feet

  “agriculture ag 5 acres (j) 200' rural non-farm residential r-”

  2 more reviewed findings on this topic

  • District specific (with conditions) — R-1 rural residential district lots inside Casco township

    “rural non-farm residential r- 2 acres (j) 150' (g) l suburban residential”

  • District specific (with conditions) — R-2 suburban residential district lots inside Casco township

    “suburban residential 2 acres (j) 150t (g) r-2 manufactured 5 acres (j) 100’ (g)”

• Building heightDistrict specific (with conditions)

  Accessory buildings in the AG, R-1 and R-2 districts inside Casco township; principal building height not yet located

  • The ordinance says height limits do not apply to farm buildings, chimneys, church spires, flagpoles, public monuments or wireless transmission towers.
  • Principal building height limits for AG, R-1 and R-2 are in the Section 59 schedule and were not read.

  accessory building maximum height: <= 35 feet (also limited to two stories)

  “accessory buildings shall not exceed two (2) stories or thirty-five (35) feet in height in the ag, r-l, and r-2 districts.”

• Manufactured homesLimited

  Manufactured homes in the RT (manufactured home residential) district inside Casco township

  • The RT district is for manufactured home parks and subdivisions; the ordinance states the RT district provides sites for manufactured homes in a higher density setting.
  • Manufactured homes in a park must be at least 5 acres where sewer and water are available, and 10 acres where they are not (Section 24).
  • Single-family dwellings, site-built or factory-built, must meet the district floor area requirements and be firmly attached to a permanent foundation (Section 80).

  minimum manufactured home park size with sewer and water: >= 5 acres (10 acres where sewer and water are not available)

  “the manufactured home residential district is designed to provide sites where manufactured homes can be placed in a higher density setting”

• Agricultural exemptionAvailable (with conditions)

  Agricultural buildings inside Casco township exempt from the state building code

  • The page says state building code requirements apply to buildings and structures except agriculturally exempt ones.
  • The qualifying criteria for an agricultural exemption were not located.

  “the state building code requirements also apply to buildings and structures (except agriculturally exempt).”

• Subdividing landRegulated (with conditions)

  Land divisions and splits of land inside Casco township

  • The zoning ordinance sets lot shape and access rules and gives the township supervisor review of land divisions.
  • State land division law (Michigan Land Division Act) may also apply; not checked.

  “the planning commission, or in the case of land divisions the township supervisor, shall interpret the intent of this section when reviewing proposed lots, parcels, division, and/or splits of land”

• Permit processPartial

  Building and zoning permit process inside Casco township

  • Applications are available at the office and on the township site (online payments through BS&A).
  • Site plan approval is required before a building permit is issued.
  • Delays are commonly caused by missing building plans and site plan drawings; the township encourages early review of building packets.

  “applications to build are available in the office during regular business hours.”

Rules another office applies inside Casco Township

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

• Building code adoptedAdopted (with conditions)

  Buildings and structures inside Casco township, as adopted by the township board

  • The page says the state building code requirements apply except agriculturally exempt buildings.
  • Specific code editions were not identified on the page.

  “the township board adopted the state of michigan building codes and we must follow the states rules and guidelines.”

• Who permits septicCounty (with conditions)

  On-site sewage disposal (septic) for land inside Casco township where sanitary sewer is not available; the St. Clair County Health Department approves it

  • The ordinance ties minimum lot width to approval of on-site sewage disposal by the county health department.
  • Geography is recorded as district-specific because the county-authority scope enum does not allow township-specific; the rule applies inside Casco township.

  “*minimum lot width is subject to approval of on-site sewage disposal by the st. clair county health department.”

• Septic permitLimited

  Two-family dwellings by special approval inside Casco township where sanitary sewers are not available

  • Requirement appears only as a special approval condition for two-family dwellings; general single-family septic permit requirement not located.
  • Issued by the St. Clair County Health Department.

  “an approved septic system permit from the st. clair county health department shall be submitted for each dwelling unit where sanitary sewers are not available.”

Still unanswered

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

• Owner-builder exemption — Owner-builder permits inside Casco township
• Certificate of occupancy — Certificate of occupancy for new homes inside Casco township
• Setbacks — Front, side and rear yard setbacks for AG, R-1 and R-2 lots inside Casco township
• Lot coverage — Maximum lot coverage for AG, R-1 and R-2 lots inside Casco township
• Living in an RV — Occupancy of recreational vehicles on private land inside Casco 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.