Unincorporated Monroe County, Illinois requires a building permit from Monroe County Zoning & Building for covered construction, and the county enforces its zoning and adopted building codes there.123 A city or village with its own zoning code can apply different zoning, but private septic permits come from the Monroe County Health Department.45
At a glance
- Building permit
- Required for covered construction and structural alterations1
- Zoning
- County zoning applies in unincorporated areas; municipal rules vary24
- Septic
- County permit required before installation or repair67
- RV living
- Parked RV living is barred outside a park; qualifying temporary use needs approval89
- Tiny home
- Classification must be confirmed; residences generally need 900 square feet10
- Accessory dwelling
- Residential use of an accessory building is prohibited11
- Owner-builder
- Homeowner electrical work permit available after a test; limited plumbing allowance1213
- Private well
- State or approved local permit required before work14
Who to call
Building permits
Monroe County Zoning & Building
Building and electrical permits, zoning, flood zoning, appeals and code enforcement
100 S. Main St., Waterloo, IL 62298
Septic permits
Monroe County Health Department — Environmental Health
Environmental health questions involving private sewage disposal and wells
beckert@monroecountyhealth.org
1315 Jamie Lane, Waterloo, IL. 62298
Contact details are copied from each office’s official page and were checked against it on October 10, 2026.
Off-grid gear
Going off-grid in Monroe County means bringing your own water and power. The kit we’d start with:
- Water Crystal Quest Filter any source — well, rain, or creek — to drinking-clean.
- Power Bluetti Solar generators and home battery backup for living off the grid.
- Septic Soil percolation test kit Run your own perc test before paying an engineer — the first thing a septic office asks about.
- Water Well water test kit Bacteria, nitrates, hardness — know what the well on a parcel is really pumping.
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Do you need a building permit in Monroe County, Illinois?
Yes. Unincorporated Monroe County requires a permit before a nonagricultural building or structure is erected, added to or structurally altered; an agricultural building also needs a permit once it costs more than $500 or exceeds 100 square feet, and that agricultural permit carries no charge if the building meets the setback line.15 A shed or carport of 100 square feet or larger needs a permit as well.16 Monroe County has adopted building codes, including the 2006 International Building Code and International Residential Code; ask Zoning & Building to confirm the electrical and plumbing editions for your project.1718
New-home construction requires 10 inspections, and the building inspector determines the inspection count for other permitted work.19 Before a regulated structure, use or lot is occupied or operated, Monroe County requires a final certificate of zoning compliance after an inspection confirms that the approved work was completed according to plan.20
Who issues building permits in Monroe County, Illinois?
Monroe County Zoning & Building is the permit office for unincorporated land; the office accepts building applications through Cloudpermit or by email or drop-off.18 Reach the office at 618-939-8681 ext. 260 or visit 100 S. Main St., Waterloo, IL 62298.18
Applicants may apply for and track permits and request inspections through Cloudpermit, or submit downloaded applications by email or drop-off at the Zoning Office.21 The published building-permit fee is $5 per $1,000 of structure value, plus inspection fees; each inspection costs $70.22 A homeowner may obtain an electrical work permit for personally performed work in an owner-occupied single-family home or duplex after passing the homeowner test, which may be taken only twice per calendar year; county electrical-code compliance and inspections still apply.12
Does Monroe County, Illinois have zoning?
Yes. County zoning applies throughout unincorporated Monroe County and inside municipalities that have not adopted their own zoning code.23 A municipality with its own zoning code may apply different local zoning rules, so verify the parcel's jurisdiction first, while septic permits stay with the Monroe County Health Department.2425 The county publishes a zoning map and district-specific regulations.26
Each lot must independently satisfy its district’s area, dimensions and setbacks; ask Zoning & Building for the applicable Schedule 2A requirements before buying.2728 Setbacks and height limits vary by district and use; in certain built-up residential or business areas, the front setback is based on neighboring development but is bounded by a 15-foot minimum and a 50-foot maximum requirement.29 The 20-foot height cap identified in the code applies to structures in manufactured-home parks, not every building countywide.30 Agricultural buildings must still meet district setbacks.31
How do septic permits work in Monroe County?
The Monroe County Health Department regulates private sewage systems for homes and facilities not served by public sewer.6 A permit is required before installing or repairing a private sewage system, and the proposal is reviewed under state requirements and the county sewage ordinance.7 Off-grid sanitation is not a way around review: sewage must go to an allowed, properly designed system.32 Call Environmental Health at 618-939-3871 ext. 212 or email beckert@monroecountyhealth.org before committing to a system design.33 A subdivision that will rely on private sewage systems also needs a Subdivision Application reviewed by the department.34
Only 11.6% of Monroe County soils are rated “not limited” for a conventional septic drain field; that countywide rating makes a site evaluation important, but does not mean septic is impossible.35 The department inspects complaints about nuisance conditions or possible failures; a property-transfer or loan inspection costs $200 and requires an application before scheduling.36
Can you live in an RV or tiny home in Monroe County?
In unincorporated Monroe County, a parked RV outside a travel-trailer park cannot contain living quarters or a business.8 The Zoning Administrator may approve temporary occupancy for up to one year for an emergency, personal hardship, construction, demolition or a related condition, subject to county conditions.9 Other temporary use needs written permission unless expressly allowed by the zoning code.37
We could not confirm a separate tiny-home classification in Monroe County; ask Zoning & Building how the proposed home would be classified, because residences generally require at least 900 square feet.38 Manufactured homes on individual lots may be permitted in R-MH with district lot sizes and setbacks, a permanent perimeter foundation and anchors, and no more than one home per lot; manufactured homes in the Agricultural District are special uses.39 Mobile homes also need at least 900 square feet, a kitchen and sanitary facilities, a full-perimeter foundation below frost depth, removed wheels and towing devices, a roof pitch of at least 3/12 and a minimum 6-inch eave overhang.40 An accessory building cannot be used as a residence; ask Zoning & Building about an attached dwelling within a principal building.11
Building a home in Monroe County: what are the steps?
- Confirm the parcel's jurisdiction and zoning district, because a municipality with its own code may apply different rules.441
- Ask Zoning & Building to confirm lot area, setbacks, height, access and flood constraints for the proposed site.42293043
- Have Environmental Health review the private sewage proposal before work begins where public sewer is unavailable.67
- Submit the building application through Cloudpermit or by email or drop-off.21
- Obtain entrance approval from the roadway's legal maintenance authority; the County Engineer approves county Highway Entrance Permits.44
- Request the required inspections and obtain the final certificate of zoning compliance before occupancy.1920
What should you check before buying land in Monroe County?
Start with jurisdiction, zoning district, legal access, septic feasibility, water and flood exposure. County zoning governs unincorporated land, while municipalities with their own codes may use different rules.4 A driveway entrance needs approval from the roadway's maintenance authority, and work in a state-highway right-of-way requires an IDOT permit before work starts.4445
For a private well, Illinois requires a permit from the state or an approved local health department before construction, modification or sealing begins.14 Flood-hazard construction receives county flood-safety review and must meet protective design requirements.43 The nearest city of 100,000 or more people is about 24 miles in a straight line from the county center.46 The effective property-tax rate is about 1.7%, and the median annual property-tax bill is $4,523.4748
Watch-outs
- Illinois allows a qualifying owner-occupant to perform plumbing on a single-family residence, but that limited allowance does not waive county permits, code compliance or inspections.1349
- A parked RV cannot be used as living quarters outside a travel-trailer park; qualifying temporary occupancy requires county approval.89
- Residential use of a detached accessory building is prohibited, and the county has not confirmed how an attached accessory dwelling would be classified.11
- Only 11.6% of Monroe County soils are rated “not limited” for a conventional septic drain field; individual lots still need evaluation, and septic is not necessarily impossible.35
Sources
- Monroe County Code of Ordinances, quoted and re-checked
- Chapter 40 Zoning Code, quoted and re-checked
- FAQ, quoted and re-checked
- Zoning & Building, quoted and re-checked
- Private Sewage Disposal Systems, quoted and re-checked
- Private Sewage Disposal Systems, quoted and re-checked
- Private Sewage Disposal Systems, quoted and re-checked
- Chapter 40 — Zoning Code, quoted and re-checked
- Chapter 40 — Zoning Code, quoted and re-checked
- Chapter 40 Zoning Code, quoted and re-checked
- Chapter 40 Zoning Code, quoted and re-checked
- Chapter 6: Building Regulations — Monroe County, IL, quoted and re-checked
- HB5913 Enrolled — Illinois Plumbing License Law amendment (Illinois statewide rule), quoted and re-checked
- 77 Ill. Admin. Code 920.130, Water Well Permit Requirements (Illinois statewide rule), quoted and re-checked
- Chapter 40 Zoning Code, quoted and re-checked
- Zoning & Building, quoted and re-checked
- Building Regulations Chapter 6, quoted and re-checked
- Monroe County Zoning & Building (monroecountyil.gov)
- Application for Building Permit, quoted and re-checked
- Chapter 40 Zoning Code, quoted and re-checked
- Permits & Forms, quoted and re-checked
- Fee Schedule, quoted and re-checked
- Chapter 40 Zoning Code, quoted and re-checked
- Chapter 40 Zoning Code, quoted and re-checked
- Private Sewage Disposal Systems, quoted and re-checked
- Zoning & Building, quoted and re-checked
- Chapter 40 Zoning Code, quoted and re-checked
- Chapter 40 Zoning Code, quoted and re-checked
- Chapter 40 Zoning Code, quoted and re-checked
- Chapter 40 Zoning Code, quoted and re-checked
- Chapter 40 Zoning Code, quoted and re-checked
- Private Sewage Disposal Systems, quoted and re-checked
- Monroe County Health Department — Environmental Health (monroecountyhealth.org)
- Private Sewage Disposal Systems, quoted and re-checked
- 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
- Private Sewage Disposal Systems, quoted and re-checked
- Chapter 40 Zoning Code, quoted and re-checked
- Chapter 40 Zoning Code, quoted and re-checked
- monroecountyil.gov, quoted and re-checked
- monroecountyil.gov, quoted and re-checked
- Zoning & Building, quoted and re-checked
- Chapter 40 Zoning Code, quoted and re-checked
- Monroe County Code of Ordinances, quoted and re-checked
- Monroe County Code of Ordinances, quoted and re-checked
- Highway Permits (Illinois statewide rule), quoted and re-checked
- Straight-line distance from the county center to the nearest city of 100,000+ people: Bolthole Index county data
- Effective property tax rate: Bolthole Index county data
- Median property tax bill: Bolthole Index county data
- 225 ILCS 320/18 — Local regulation; Department standards (Illinois statewide rule), quoted and re-checked
Written October 10, 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.