Building permits, zoning and septic rules in Wonder Lake, Illinois

At a glance

Building permit

Handled by the village building department; code is the 2021 IRC and IBC¹⁴

Zoning

The village has its own zoning ordinance; district rules not confirmed²

Septic

Permit required from the McHenry County Department of Health³⁵

Subdivision

Regulated by the village's subdivision ordinance⁶

Wells

A well permit is required statewide from IDPH or an approved local health department⁷

Who to call

Contact details are copied from each office’s official page and were checked against it on October 17, 2026.

Do you need a building permit in Wonder Lake, Illinois?

Building permits inside the Village of Wonder Lake come from the village, not from McHenry County. The village building department reviews applications for code compliance, approves them or sends back corrections, and issues the permit once the fee is paid⁸. The village has adopted the 2021 IRC and IBC, the 2021 IECC and the 2023 NEC¹. Fees are listed in a village fee schedule, and online or credit-card payment adds a convenience fee⁹. The village also asks applicants to allow extra review time when it is busy⁴.

Who issues building permits in Wonder Lake, and how do you reach them?

The Village of Wonder Lake Building Department sits in Village Hall at 4444 Thompson Road⁴. Call 815-728-7725 or email building@wlvillage.org⁴. The village uses B&F Construction Code Services for plan reviews and inspections⁴. Illinois does not issue building permits for privately funded construction; the local unit of government does¹⁰. McHenry County's building division serves only unincorporated land, so it is the wrong counter for a lot inside village limits¹¹.

Does Wonder Lake have zoning, and what does it mean for RVs and tiny homes?

The Village of Wonder Lake has its own zoning ordinances, a zoning map and a planning and zoning commission². Subdivision of land inside the village is governed by the village's subdivision ordinance⁶. We could not read the district rules, so we cannot say what Wonder Lake allows for RV living, tiny homes, minimum lot size, setbacks or accessory dwellings. Ask Village Hall at (815) 728-0839¹² for the district of the parcel and what it permits before you buy. McHenry County's RV and lot-size rules apply only to unincorporated land and do not carry into the village¹³.

How do septic permits work in Wonder Lake?

Septic permits for Wonder Lake addresses come from the McHenry County Department of Health, Environmental Health Division³. A permit is required to install, modify, extend, repair, replace or abandon a septic system, and applications go in by mail or in person⁵. Installers must be IDPH-licensed, and a new system needs a soil boring report from a certified soil classifier⁵. Surface-discharging systems are not allowed in the county, and holding tanks are allowed only in very limited cases¹⁴. Soils matter here: only a small share of McHenry County soils rate well for a conventional drain field, so expect a site evaluation and possibly an engineered system¹⁵. Whether a given village lot is on sewer, we could not confirm; the village water department can tell you.

Building a home in Wonder Lake: the steps, in order

1. Ask Village Hall which zoning district the parcel is in and what it allows¹².
2. If the lot needs septic, get a site evaluation with a soil boring report from the McHenry County Department of Health⁵.
3. Apply for the building permit with the village building department⁸.
4. Schedule inspections through the village's inspection contractor⁴.
5. Confirm occupancy requirements with the village, since we could not confirm how occupancy certificates work there.

What stays with McHenry County, and what to check before you buy

Outside village limits the rules change: the county issues building permits and zoning for unincorporated land only, and the county's own answers are on the McHenry County page. Septic stays with the county health department either way³. A driveway onto a county highway needs a county access permit¹⁶. Wells need a permit from IDPH or an approved local health department⁷. Floodplain status of a specific lot, owner-builder rules and driveway rules inside the village are unconfirmed, so ask Village Hall. McHenry County's effective property tax rate is¹⁷% and its median bill is $¹⁸ a year.

Watch-outs

• We could not read Wonder Lake's zoning district rules, so RV, tiny-home, lot-size and setback questions need a call to Village Hall at (815) 728-0839 before you buy¹².
• The county's septic permit covers addresses inside the village, so a village building permit does not replace it³.
• Whether the village requires occupancy certificates or allows owner-built homes is unconfirmed; ask the building department⁴.

Sources

1. Building - Village of Wonder Lake (Village of Wonder Lake), quoted and re-checked
2. Planning and Zoning - Village of Wonder Lake (Village of Wonder Lake), quoted and re-checked
3. Onsite Wastewater Treatment Systems (Septic Systems) - McHenry County Department of Health (Village of Wonder Lake), quoted and re-checked
4. Village of Wonder Lake Building Department (villageofwonderlake.org)
5. Onsite Wastewater Treatment Systems (Septic Systems) - McHenry County Department of Health (Village of Wonder Lake), quoted and re-checked
6. Subdivision Ordinance 97 - Village of Wonder Lake (Village of Wonder Lake), quoted and re-checked
7. 77 Ill. Admin. Code 920.130, Water Well Permit Requirements (Illinois statewide rule), quoted and re-checked
8. Building Permit - Village of Wonder Lake (Village of Wonder Lake), quoted and re-checked
9. Building Permit - Village of Wonder Lake (Village of Wonder Lake), quoted and re-checked
10. Illinois Codes FAQ (Illinois statewide rule), quoted and re-checked
11. codelibrary.amlegal.com, quoted and re-checked
12. Village of Wonder Lake Planning and Zoning (villageofwonderlake.org)
13. codelibrary.amlegal.com, quoted and re-checked
14. Onsite Wastewater Treatment Systems (Septic Systems) - McHenry County Department of Health (Village of Wonder Lake), quoted and re-checked
15. 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
16. Highway Access Permit Application, quoted and re-checked
17. Effective property tax rate: Bolthole Index county data
18. Median property tax bill: Bolthole Index county data

Written October 17, 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.