Zoning, building permits and septic rules in Algonquin Township, Illinois

Rules another office applies inside Algonquin Township

Algonquin 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

  New construction permits on unincorporated land inside Algonquin township, under McHenry County building codes (villages and cities excluded)

  • The county ordinances page lists the 2021 International Residential Code with ordinance and amendments as an adopted building code.
  • The same page states that effective January 1, 2023 all new building permit applications are reviewed for compliance with the 2021 ICC codes and the 2020 NEC.
  • The county amendment text linked from that page was not opened.

  code edition: 2021 International Residential Code (with local ordinance and amendments)

  “2021 international residential code: ordinance and amendments”

• Zoning districtsPublished (with conditions)

  County zoning districts for unincorporated land inside Algonquin township

  • The county publishes an interactive GIS map and zoning district look-up.
  • The district use and dimensional text in the county Unified Development Ordinance was not opened.
  • Districts apply only to unincorporated land; village and city land is excluded.

  “interactive gis map and zoning district look-up”

• Who permits septicCounty (with conditions)

  Onsite septic systems on unincorporated land inside Algonquin township; the McHenry County Department of Health administers the permit. Land inside a village may follow that municipality's rules.

  • The county health page describes septic permitting by the McHenry County Department of Health.

  “a permit is required from the mchenry county department of health to install, modify, alter, extend, repair, replace or abandon a septic system in mchenry county.”

• Septic permitRequired

  Installing, modifying, extending, repairing, replacing or abandoning a septic system on unincorporated land inside Algonquin township

  • The septic FAQ says a permit application may be submitted in person or by mail.
  • Required application materials vary by permit type; not read.

  “a permit is required from the mchenry county department of health to install, modify, alter, extend, repair, replace or abandon a septic system in mchenry county.”

• Permit feesPublished (with conditions)

  County building and zoning permit fees for unincorporated land inside Algonquin township

  • The county planning page announces a new fee schedule effective July 1, 2026.
  • The fee amounts in that schedule were not opened.
  • The same page states that effective December 1, 2022 the department accepts only credit, check, money order or exact cash.

  “new fee schedule effective july 1, 2026 interactive gis map and zoning district look-up”

• Permit processPartial

  County permit process for unincorporated land inside Algonquin township; villages and cities run their own permits

  • Online permit applications are available through a permit application portal with a guide.
  • The planning page says villages or cities should be contacted for property inside their limits.
  • Step-by-step process and review timelines were not read.

  “online permit applications permit application portal guide”

Still unanswered

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

• Owner-builder exemption — Owner-builder construction on unincorporated land inside Algonquin township
• Certificate of occupancy — Certificate of occupancy on unincorporated land inside Algonquin township
• Local zoning — Whether Algonquin township adopts its own zoning ordinance for land inside the township limits
• Minimum dwelling size — Minimum dwelling size in the main single-family residential district and the agricultural district on unincorporated land inside Algonquin township
• Minimum lot size — Minimum lot size in the main single-family residential district and the agricultural district on unincorporated land inside Algonquin 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.