Building permits in McHenry County, Illinois
Find the right authority before you build. McHenry County permitting follows Illinois law — here is exactly who issues the permit and where to start.
County + cities (mixed)
McHenry County Planning & Development — Building Division (unincorporated areas); municipalities issue their own permits
The McHenry County Building Division issues building permits and conducts inspections for all unincorporated areas of McHenry County. Properties inside a village or city (e.g., Crystal Lake, McHenry, Woodstock) are permitted by that municipality, not the county.
Open the official permit portal →
Apply through the county’s online permit portal; stormwater review is concurrent with building review.
Check a home project's permit in McHenry County, Illinois
Select a project to see its Illinois permit rule. Whether the county or your city issues it depends on incorporation status — see the authority note above.
Illinois
Exact permit fees are set by the local building department. WikEst shows the published or code-based range where one exists, linked to its official source — verify the final amount at the source before budgeting.
🏠 Accessory Dwelling Unit (ADU) permit fee in Illinois
Permit requiredCase by casecity authority
Permit fee range
No flat statewide fee; Chicago calculates fees from construction type, occupancy, square footage, and scope via its online calculator. Other municipalities set their own fees.
Typical timeline
Varies
Setback
—
Exempt if
Not size-exempt
Illinois has no statewide building code; most municipalities use the IRC while Chicago enforces the 2019 Chicago Building Code. ADUs require a building permit plus local zoning approval — Chicago and other cities regulate ADUs through zoning. Verify with your municipality.
Official sources: City of Chicago — Guide to Building Permits (2019 Chicago Building Code) · ICC — Illinois Codes (no statewide code; local adoption)
Representative cities for Illinois: Chicago, Springfield.
All 20 project fee ranges in Illinois
Official-source ranges where published; “By local jurisdiction” means no flat fee is published and the amount is set case by case.
| Project | Permit? | Authority | Fee range | Go / no-go |
|---|---|---|---|---|
| 🏠 Accessory Dwelling Unit (ADU) | yes | city | No flat statewide fee; Chicago calculates fees from construction type, occupancy, square footage, and scope via its online calculator. Other municipalities set their own fees. | case-by-case |
| 🪵 Deck / Porch | yes | city | Chicago fees via online calculator; other municipalities set their own. | allowed |
| 🧱 Fence / Wall | conditional | city | Set by local jurisdiction | allowed |
| 🛖 Shed / Outbuilding | conditional | city | Set by local jurisdiction | allowed |
| 🪜 Basement Finish | yes | city | Municipal building permit fee; varies with scope. | allowed |
| 🚗 Garage / Carport | yes | city | Municipal building permit fee. | allowed |
| ☀️ Rooftop Solar PV | yes | city | Electrical/structural permit fee set by municipality. | allowed |
| 🌡️ HVAC Replacement | yes | city | Mechanical permit fee set by municipality. | allowed |
| 🍳 Kitchen Remodel | yes | city | Building permit fee; trade permits billed separately. | allowed |
| 🛁 Bathroom Remodel | yes | city | Building permit fee; trade permits billed separately. | allowed |
| 🏗️ Room Addition | yes | city | Building permit fee based on valuation; zoning and plan review apply. | allowed |
| 🪟 Window / Door Replacement | conditional | city | Set by local jurisdiction | allowed |
| 🏘️ Roof Replacement | yes | city | Roof-covering permit fee set by municipality. | allowed |
| 🅿️ Driveway / Parking Pad | conditional | city | Set by local jurisdiction | allowed |
| 🏊 Swimming Pool / Spa | yes | city | Building permit fee; barrier fencing required by code. | allowed |
| 🧱 Retaining Wall | conditional | city | Set by local jurisdiction | allowed |
| 💥 Demolition / Teardown | yes | city | Demolition permit fee set by the municipality; verify locally. | allowed |
| 🚰 Septic System | yes | county | Private sewage permit fees set by the local health department; verify locally. | allowed |
| 🔌 EV Charger | conditional | city | Electrical permit fee set by the municipality; verify locally. | allowed |
| ⚡ Standby Generator | yes | city | Electrical (and often mechanical/gas) permit fee set by the municipality; verify locally. | allowed |
Permit cheat-sheet (Illinois rules)
| Project | Permit? | Authority | Typical fee | Timeline | Go / No-Go | Key notes |
|---|---|---|---|---|---|---|
| 🏠 Accessory Dwelling Unit (ADU) | Permit required | city | No flat statewide fee; Chicago calculates fees from construction type, occupancy, square footage, and scope via its online calculator. Other municipalities set their own fees. | — | Case by case | Illinois has no statewide building code; most municipalities use the IRC while Chicago enforces the 2019 Chicago Building Code. ADUs require a building permit plus local zoning approval — Chicago and other cities regulate ADUs through zoning. Verify with your municipality. |
| 🪵 Deck / Porch | Permit required | city | Chicago fees via online calculator; other municipalities set their own. | — | Generally allowed | Decks and porches require a permit (Chicago requires permits for decks/porches). Chicago offers an Express Permit for eligible deck work; most other IL towns follow IRC R105. |
| 🧱 Fence / Wall | Conditional | city | — | — | Generally allowed | Chicago requires a permit for fences (handled via the Express Permit Program). Other Illinois municipalities often exempt fences at or below 6 ft. Verify locally. |
| 🛖 Shed / Outbuilding | Conditional | city | — | — | Generally allowed | Larger sheds and any shed with utilities require a permit. Confirm the threshold with your local building department. Exempt: Under ~120 sq ft typically exempt under the IRC; varies by municipality. |
| 🪜 Basement Finish | Permit required | city | Municipal building permit fee; varies with scope. | — | Generally allowed | Finishing a basement into habitable space requires permits for egress, framing, electrical, plumbing, and mechanical work. Sleeping rooms need code-compliant egress. |
| 🚗 Garage / Carport | Permit required | city | Municipal building permit fee. | — | Generally allowed | A new garage requires a permit. Chicago’s Easy/Express Permit covers private (detached frame) garages; elsewhere a standard building permit applies. |
| ☀️ Rooftop Solar PV | Permit required | city | Electrical/structural permit fee set by municipality. | — | Generally allowed | Rooftop solar PV requires an electrical and structural permit. Chicago’s Express Permit covers small-scale residential solar PV; other municipalities issue a solar/electrical permit. |
| 🌡️ HVAC Replacement | Permit required | city | Mechanical permit fee set by municipality. | — | Generally allowed | Furnace, AC, or heat-pump replacement requires a mechanical (HVAC) permit and inspection. Chicago requires a city-licensed mechanical contractor. |
| 🍳 Kitchen Remodel | Permit required | city | Building permit fee; trade permits billed separately. | — | Generally allowed | A permit is required when relocating plumbing/electrical, moving walls, or changing fixtures. Cosmetic-only work may be exempt. |
| 🛁 Bathroom Remodel | Permit required | city | Building permit fee; trade permits billed separately. | — | Generally allowed | A permit is required when relocating plumbing/electrical, moving walls, or changing fixtures. Cosmetic-only updates may be exempt. |
| 🏗️ Room Addition | Permit required | city | Building permit fee based on valuation; zoning and plan review apply. | — | Generally allowed | Room additions change the footprint and require a full building permit and zoning approval. Chicago uses the 2019 Chicago Building Code for plan review. |
| 🪟 Window / Door Replacement | Conditional | city | — | — | Generally allowed | Swapping windows or exterior doors in the same opening is usually permitted via an expedited process; enlarging openings requires a full permit. |
| 🏘️ Roof Replacement | Permit required | city | Roof-covering permit fee set by municipality. | — | Generally allowed | Re-roofing is covered by Chicago’s Express Permit; elsewhere a roofing permit is required. Minor repairs may be exempt. |
| 🅿️ Driveway / Parking Pad | Conditional | city | — | — | Generally allowed | A permit may be required where the driveway connects to the street/right-of-way or triggers an excavation/erosion permit. Verify locally. |
| 🏊 Swimming Pool / Spa | Permit required | city | Building permit fee; barrier fencing required by code. | — | Generally allowed | Pools require a permit and barrier. Chicago processes pools via its Express/specialty permit programs; other municipalities issue a standard permit. |
| 🧱 Retaining Wall | Conditional | city | — | — | Generally allowed | Height and whether the wall supports a surcharge (driveway, structure, or slope above) determine the permit threshold. Verify with your municipality. |
| 💥 Demolition / Teardown | Permit required | city | Demolition permit fee set by the municipality; verify locally. | — | Generally allowed | A full teardown or major strip-out requires a demolition (building) permit from the municipality. Illinois has no statewide building code, so Chicago and other cities issue the permit under their locally adopted code; unincorporated areas are permitted by the county. Demolition permits often require utility disconnects and, for older homes, asbestos/lead clearance. |
| 🚰 Septic System | Permit required | county | Private sewage permit fees set by the local health department; verify locally. | — | Generally allowed | New or replacement onsite wastewater (private sewage / septic) systems require a permit from the local health department under the Illinois Private Sewage Disposal Code (77 Ill. Adm. Code 905). Engineered design and a site/perc evaluation are required; the local health department is the permitting authority. |
| 🔌 EV Charger | Conditional | city | Electrical permit fee set by the municipality; verify locally. | — | Generally allowed | A home EV charging station needs an electrical permit (dedicated 240V circuit and wall unit) issued by the municipality. Illinois has no single statewide EV-permitting fast-track, so review time varies by city (Chicago processes through its permits program). Work must meet the NEC. |
| ⚡ Standby Generator | Permit required | city | Electrical (and often mechanical/gas) permit fee set by the municipality; verify locally. | — | Generally allowed | A permanently installed standby generator with a transfer switch and fuel (gas/propane) line requires electrical and often mechanical/gas permits, plus inspection. Setback, noise, and carbon-monoxide rules may apply, and HOAs may restrict installation. Verify with the municipality (e.g., Chicago DOB). |
Frequently asked questions
Who issues building permits in McHenry County, Illinois?
McHenry County Planning & Development — Building Division (unincorporated areas); municipalities issue their own permits is the permitting authority for McHenry County. Permitting is split — cities issue for incorporated areas, the county for unincorporated areas. Start at the official portal linked above.
Do I go to the county or my city for a building permit in McHenry County?
Permitting is split — cities issue for incorporated areas, the county for unincorporated areas.
What home projects need a permit in McHenry County?
The same project types shown in the cheat-sheet above (ADU, deck, fence, shed, solar, and more) — rules follow Illinois state law. Whether the county or your city issues it depends on your property's incorporation status.
How do I apply for a permit in McHenry County?
Use the official permit portal linked above. Most offices accept online submissions; have your plans, site information, and contractor details ready before applying.
Sources: McHenry County Planning & Development — Building Division · ICC — Illinois Codes (no statewide code; local adoption) · Illinois Capital Development Board — Building Codes · City of Chicago — Guide to Building Permits (2019 Chicago Building Code) · City of Chicago Dept. of Buildings — Permits