Zoning, building permits and septic rules in Big Rock Township, Illinois

Big Rock Township’s own rules

• Building permitRequired

  New construction, remodeling, repair, or demolition on unincorporated land inside Big Rock Township.

  • Applicant must submit the 2026 Building Permit Application and additional required documents through the Kane County Web Portal; payment is due after approval.
  • Special accommodations may be made when a digital application cannot be submitted.

  “Building permits are required for all new construction, remodel, repair or demolition projects on properties in unincorporated Kane County.”

• Subdividing landRegulated (with conditions)

  Divisions or redivisions of unincorporated parcels inside Big Rock Township.

  • A division or redivision into two or more parts by mapping, platting, conveyance, or boundary change/rearrangement is generally considered a subdivision.
  • Concept plans, preliminary plans, improvement plans, and final plats are processed under the County Subdivision Regulations.

  minimum number of resulting parts: >= 2 parts (The County page states this is the general definition of a subdivision.)

  “In general, any division or redivision of a parcel of land into 2 or more parts [...] is considered a subdivision.”

• Permit processPublished (with conditions)

  Building-permit applications for unincorporated land inside Big Rock Township.

  • Additional required documents must accompany the application through the Kane County Web Portal.
  • Special accommodations may be made if a digital application cannot be submitted.
  • Payment is due after permit approval.

  “submit your application and any additional required documents via the electronic Kane County Web Portal.”

Rules another office applies inside Big Rock Township

Big Rock Township 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 septicLocal (with conditions)

  Private sewage systems on land inside Big Rock Township served by the Kane County Health Department.

  • Municipal review or approval may separately be required for some pool or structure work on a property with septic.

  “Please call 630-444-3040 to request a private sewage/septic inspection or permit.”

• Septic permitRequired

  A new or repaired private septic system on land inside Big Rock Township served by the Kane County Health Department.

  • All septic work requiring a permit must be completed by a licensed septic contractor, including work on a homeowner's own property.
  • A soil evaluation is required with every application for a new system or renovation involving the septic field; tank replacements do not require a soil evaluation.

  “a KCHD septic permit is required. All septic work requiring a permit must be completed by a licensed septic contractor.”

• Off-grid sanitationLimited

  Alternative private sewage systems inside Big Rock Township served by the Kane County Health Department.

  • A property with accessible public sewer must connect unless the pipe requirement exceeds 4 inches or an undue hardship exists.
  • If soil is unsuitable for a properly sized subsurface system, an alternative system is required.

  “If the soil is not suitable for a properly sized subsurface system, alternative systems, including aerobic treatment units, will be required.”

• Mandatory utility hookupSewer (with conditions)

  New private-sewage proposals inside Big Rock Township served by the Kane County Health Department.

  • Connection is required unless access to public sewer requires more than a 4-inch pipe or creates an undue hardship.
  • When hardship exists, documentation must accompany the KCHD septic-permit application.

  public-sewer connection pipe threshold: > 4 inches (Connection is not required where access creates an undue hardship; documentation is required with the septic-permit application.)

  “Unless access to public sewer requires more than a 4-inch pipe or creates an undue hardship, you will need to connect to public sewer.”

Still unanswered

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

• Owner-builder exemption — Residential building work inside Big Rock Township.
• Inspections — Building work inside Big Rock Township.
• Certificate of occupancy — New or altered dwellings inside Big Rock Township.
• Minimum dwelling size — Dwellings on unincorporated land inside Big Rock Township.
• Minimum lot size — Residential lots on unincorporated land inside Big Rock 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.