DuPage County is a patchwork of villages, cities, and unincorporated pockets. On a sign job there, settle one question before sizing anything: is the lot inside a municipality or in unincorporated county territory? That decides which ordinance, which permit office, and which inspector you deal with. In Addison the village has a full sign chapter of its own, the county has one too, and the two meet along irregular boundaries.
How Illinois splits the territory
County zoning in Illinois stops at the line of any city, village, or incorporated town that has its own zoning ordinance. The Counties Code, 55 ILCS 5/5-12001, gives county boards zoning power over territory “outside the limits of cities, villages and incorporated towns which have in effect municipal zoning ordinances.” Municipalities get their own zoning powers under 65 ILCS 5/11-13-1, including the power “to divide the entire municipality into districts.”
DuPage County's zoning ordinance draws the same line from its side. Section 37-403 of the county code says its provisions “shall apply to all properties in unincorporated DuPage County,” and the county's sign article (section 37-1103.A.17) routes sign permits to the DuPage County Building Department. Even the county's zoning lookup is labeled “For County or Unincorporated Zoning ONLY.”
Addison also has home-rule powers. The Illinois Constitution, Article VII, section 6(a), makes municipalities of more than 25,000 people home-rule units, and the Census Bureau counted 35,702 residents in Addison village in 2020. Home rule does not decide which code applies; that follows from the county statute above. It widens what the village may regulate inside its own limits.
Three free checks for an address
We ran all three against Addison's Village Hall, 1 Friendship Plaza, on September 28, 2026. None requires an account.
- Census geocoder. The Census geographies geocoder matched the address and returned “Addison village” under Incorporated Places. It also returned “Addison township,” which is a separate unit of government in Illinois and not the village; do not confuse the two.
- DuPage County municipal layer. The county publishes its GIS layers through its interactive map gallery, including a Parcel Viewer. Querying the county's municipality layer at the Village Hall point returned CITY: Addison.
- DuPage County unincorporated zoning layer. The same point returned no feature from the county's unincorporated zoning layer. That is what you expect for a lot inside a village: the county has no zoning district there to report.
When all three agree, you can move on with reasonable confidence. When they disagree, or the lot sits on an edge, stop and ask. The county describes its municipality layer as tax-code polygons, and the Census geocoder estimates position from address ranges; neither is an annexation record. The village's Community Development staff or the county zoning office can confirm a specific parcel.
Reading Addison's Chapter 27
The village keeps its sign regulations in Chapter 27 of the Village Code, published as a PDF on the village website, which we read on September 28, 2026. The permit rule is section 27-202: “It is unlawful for any person to erect, construct, alter or relocate any sign with [sic] the Village without first obtaining a permit from the enforcement official and paying the fee required.” The same section says maintenance, or changing parts designed to be changed, is not an alteration, so long as the change does not alter the surface area or height or make the sign nonconforming.
Two street lists that look alike and are not
Section 27-104 defines two terms that sound interchangeable. “Major commercial street frontage properties” are properties on Addison Road, Army Trail Road, Grace Street, Fullerton Avenue (west of Addison Road, including Collins Street), Lake Street, North Avenue, Rohlwing Road, and Swift Road. “Major street frontage” means the street at the front of the building plus a named list that leaves out Grace Street and Collins Street. Because the second term also covers whatever street the building faces, the gap matters mainly for a building that fronts another street and has a side or rear on Grace Street or Collins Street.
It matters because the chapter uses both terms. In section 27-413, a freestanding sign on major commercial street frontage needs an above-grade base, support structure, or pole cover of approved masonry or concrete; elsewhere the requirement is approved noncombustible materials. The manufacturing-district wall-sign rules, by contrast, count signs per “major street frontage exposure.” Before you apply any allowance, check which defined term the section uses and which list that term points to.
How the village measures a wall sign
The same definitions section says a wall sign's area is “within a single, continuous perimeter composed of any straight line geometric fixture which encloses the extreme limits of the advertising message.” Two details follow in the text. If the sign has a frame, box, or background board, its outside dimension sets the area. And for a sign made of individual letters, each word is measured as a rectangle, the height of the tallest letter times the length of the word, and the words are added together. The text does not say whether that is the tallest letter in each word or in the whole sign, so ask the village if the letter heights vary. We work through what that does to a sample shape in one wall sign, three measuring rules.
The record to keep for a DuPage job
| Field | What to write down |
|---|---|
| Jurisdiction | Village or unincorporated county, with the three check results and the date. |
| Code and section | Village Chapter 27 or county Chapter 37, Article XI, with the copy you read. |
| Frontage class | Which street list the lot is on, and which defined term each cited section uses. |
| Measurement basis | Perimeter, background board, or letter-by-letter, with the drawing it was measured from. |
| Permit office | Village permit portal or DuPage County Building Department. |
The same method applies wherever villages and unincorporated land sit side by side; see when the county code governs instead of the city for how other states handle it, and use the authority and source worksheet to keep the record.
This is general research guidance, not a permit decision for any property. Sources were read on September 28, 2026; the village and the county control current requirements, and the village code can be amended at any time.