In unincorporated Winnebago County, the number of houses a parcel can hold is set by a 40-acre grid, not by a minimum lot size. Chapter 90 of the county code, the Unified Development Ordinance, allows one single-family house per undivided quarter-quarter section in its AG, A-1 and A-2 farm districts, and the ordinance defines a quarter-quarter section as exactly or nearly 40 acres. This guide walks through those steps for anyone comparing land for sale in Rockford and the country parcels around it.

It covers county rules only. Inside the limits of Rockford, Loves Park, Roscoe and the other municipalities, the municipality runs planning and zoning, and different rules apply. The county's Planning and Zoning staff say so directly: if a property sits within a village or municipality, the governing village or municipality provides the planning, zoning and subdivision service. So the first question on any parcel is which jurisdiction answers for the address. Gambino Realtors has been in business since 1923 and is based in Rockford, and that question comes before every other one.

How County Zoning Counts Houses on Rural Land

The county sorts rural land into a handful of districts, and four of them matter to someone looking for acreage. The AG Agricultural Priority District and the A-1 Agricultural District both exist to protect farming and to keep farmland away from incompatible residential development. The A-2 District is for businesses that serve agriculture. The OS Open Space District is meant for public and private open space and is not intended primarily for new development. Alongside these sits the R-A Rural Agricultural Residential District, which is the county's large-lot residential district and which is covered further down.

Read the stated purpose of the farm districts before you read the numbers. Article 7 of the ordinance says the districts are meant to prevent the conversion of agricultural land to scattered residential development. That purpose explains the rest. The ordinance does allow houses in these districts. It manages their number and location with the quarter-quarter rule instead of a fixed acreage.

The quarter-quarter rule, in plain terms

A single-family dwelling is a permitted use in AG, A-1 and A-2, but it must meet one of the standards in Section 7.7.2. The first standard is the base rule. One house is allowed on an entire vacant, undivided quarter-quarter section. The lot must have at least 250 feet of frontage on a public road, or on a private road created by a recorded plat of subdivision. The house must also sit at least 1,320 feet from any feedlot or concentrated animal feeding operation of 50 animal units or more. The ordinance does not make an exception for an operation that sits on a neighboring parcel.

An additional house in the same quarter-quarter is possible, but only if the owner can prove the new lot is a poor fit for farming. The ordinance asks for clear and convincing evidence, and it names the proof. Either 80 percent or more of the proposed lot must be non-prime farmland as the County Soil and Water Conservation District defines it, or significant manmade or natural barriers must make agricultural use unsuitable. The entire quarter-quarter also has to have been one undivided parcel of record as of June 24, 1982. The new lot must be suitable for a septic system, it must stay 1,320 feet from feedlots, and it has to be created through a State Plat Act exception.

There are two more routes, and they depend on where the land sits. In the AG district, an additional house is allowed on an entire vacant, undivided half of a quarter-quarter section if the owner records a deed restriction that keeps an adjacent agriculturally zoned quarter-quarter in agricultural use for at least 99 years, subject to County Administration's approval. In the A-1 district, land within 1.5 miles of an incorporated municipality, or within half a mile of a hamlet's growth area on the county's future land use map, can carry one house per entire vacant, undivided half of a quarter-quarter section. Half of a quarter-quarter is roughly 20 acres. A parcel that is a full quarter-quarter and one that is half of a quarter-quarter are treated very differently.

Older lots and the 1982 date

June 24, 1982 appears again and again in this section of the ordinance, and it matters to anyone buying a small old parcel. A single-family dwelling is permitted on a vacant lot of record that was duly recorded with the Winnebago County Recorder as of that date and has been unaltered since. Such a lot needs only 30 feet of frontage on a public road or plat-created private road, far less than the 250 feet the base rule asks for. It still has to clear the 1,320-foot feedlot distance. If the lot was split or altered after that date, you lose this route and the base rules apply.

The ordinance also sets a ceiling. The maximum density is two single-family dwelling units or buildable zoning lots per quarter-quarter section, with no more than one in each half. And a lawfully established home that predates zoning can have its lot reduced in area or frontage and remain conforming, as long as the lot area complies with septic regulations and the frontage is at least 250 feet. Ask Planning and Zoning at (815) 319-4350 which standard a given parcel would be measured against, and ask for it in writing.

Lot size, setbacks and what you can build

In the AG, A-1 and A-2 districts, the ordinance sets no fixed minimum lot area for a single-family dwelling. The table sends you to Section 7.7.2 instead, and for agriculture it says there is no minimum but the lot remains subject to the State Plat Act and to any applicable septic and well regulations. If you read the Boone County version of this question, buying land in Boone County, you will see a district-by-district acreage table. Winnebago works differently.

The yard standards in the three farm districts are the same. Front yard 30 feet, interior side yard 10 feet, corner side yard 30 feet and rear yard 25 feet. A single-family dwelling may be 35 feet tall and may cover up to 40 percent of the lot with impervious surface. Detached accessory structures follow a separate section. None may be built before the principal building. Each is capped at 20 feet tall or the height of the house, whichever is less, except agricultural structures such as barns and silos, which have no height limit. They must sit at least 2.5 feet from rear and side lot lines, and the combined footprint of detached buildings in the rear yard may not exceed 40 percent of the required rear yard.

One more limit is easy to miss. In the AG, A-1 and A-2 districts, there may be no more than one dwelling on a zoning lot. The ordinance allows a household to keep living in an existing house or mobile home while a new house is built, but the old one must be removed by the date the certificate of occupancy is issued for the new house, or within one year after the building permit is issued, whichever comes first. Anyone planning to build next to the old farmhouse and keep both should hear that before closing.

The R-A district and its three sub-districts

The R-A District is where many of the county's older rural subdivisions sit. It absorbed the former R-E, R-R and R-A districts as sub-districts, and the ordinance recognizes the lots and homes built under those older rules as legal and conforming. The standards differ by sub-district. The RA-RA sub-district requires 2.5 acres for existing lots and 3 acres for lots created after the ordinance took effect, with 200 feet of width and a 75-foot rear yard. RA-RE requires 1 acre and 125 feet of width. RA-RR requires 25,000 square feet and 100 feet of width.

New R-A zoning is deliberately hard to get. The ordinance allows it only if the land is developed as a minor subdivision, or if no more than four buildable lots are created through the plat act, and it says no variances from that requirement are permitted. The ordinance also notes that the low density of the R-A District will generally allow on-site septic systems and wells, in accordance with the Health Department's rules. That connects the zoning question to the next one.

Well and Septic: Approvals Before You Build and Checks Before You Buy

Outside the service area of a public water and sewer system, the house brings its own utilities, and the ordinance regulates both. It requires a zoning permit before anyone digs or drills a well and before anyone installs, adds to or repairs a sewerage disposal system. The application asks for the property's PIN or address, the owner and applicant, and a dimensioned drawing of the building plot. The county's own form also asks whether the site will be served by well, septic, public water or public sewer, and how many acres of soil will be disturbed.

The Winnebago County Health Department then oversees the contractors and the work. Its inspectors oversee licensed well and septic contractors to ensure proper installation and repair, and they conduct loan inspections and site verifications. Two of the services on the department's additional-services form show how the checks work. The first is the soil boring site evaluation, which verifies that existing soil boring locations have not been compromised when the borings are more than five years old. The second is the septic system field, tank and well distance verification, which checks how far an existing system sits from a proposed building, addition or pool. The county also has a separate zoning clearance form for soil borings, so the zoning office is part of the sequence too.

Here is the order that follows from the county's own pages. Start with zoning, including the zoning clearance for soil borings, because the building officer will not issue a building permit unless the project conforms to an approved zoning permit. Then work with the Health Department, which requires a site verification for any property with a private well or septic system when the work needs a building permit. Then apply for the building permit.

If a well or septic cannot meet the code

Some parcels cannot satisfy every state and county standard for a well or septic installation. The Health Department accepts a well and septic variance petition for those cases, and its page says plainly that approvals are subject to review and are not guaranteed. Because approval is not guaranteed, confirm that a parcel can take a septic system before you rely on a building plan. The same department also reviews plats, which is where lot sizes are checked for proposed new subdivisions without public water or sewer.

Buying a home that already has a well and septic

For a house on acreage, the existing systems are the largest unknown. The Health Department recommends having a septic system inspected before you purchase, and it conducts the inspections that a mortgage lender requires on a property with a private well or septic system. Ask for the "as built" drawing of the septic system, which you can request from the local health department. It shows where the tank and the drainfield are, and that location determines where a garage, pool or addition can go.

The health department's care guidance doubles as a checklist for a purchase. The average septic system lasts 15 to 40 years, and the department recommends an inspection by a licensed contractor every three years and pumping as necessary, generally every three to five years. A well casing should rise at least eight inches above the ground surface. The department recommends testing a well once a year for coliform bacteria, nitrates and nitrites, and any other contaminants of local concern, and again whenever taste, odor or appearance changes. Water samples have to be dropped at the City of Rockford Environmental Laboratory, and the sample bottles are available at several township and village sites around the county.

A seller's disclosure report adds one more layer. The Illinois form asks the seller whether they are aware of material defects in the well or well equipment, unsafe conditions in the drinking water, and material defects in the septic or other disposal system. It also asks about underground fuel storage tanks and boundary or lot line disputes. The form is not a warranty, and it does not limit the buyer's right to contract for a property as is. See the seller disclosure report explained for Rockford homes for how it works, and see the Machesney Park guide to water, sewer and private wells for how private wells and septic systems are handled in another part of Winnebago County.

Buyers should also know what happens when public sewer reaches a property. When a home connects to the public sewer, the county's Private Sewage Disposal Code requires the old septic tank to be closed properly. A licensed plumber must handle it, the tank must be pumped by a licensed septic pumper, the top and one side must be collapsed, and the void filled with sand, gravel or similar material.

The Driveway, Building Permits, Stormwater and Assessment

On a county-maintained road, the Highway Department requires a permit before installation of any driveway starts, and the same permit covers improving or modifying an existing driveway. Applications go to the Highway Department's permit technician at (815) 319-4000. The department's page speaks only about county-maintained roads, so ask who maintains the road in front of a specific parcel before you assume the county permit is the whole answer.

On the building side, the county's Building Division serves unincorporated Winnebago County and also the villages of Cherry Valley, Durand, New Milford, Rockton and Roscoe and the City of South Beloit. Its codes page, dated April 1, 2016, lists the 2015 International Building and Residential Codes, the 2014 National Electric Code and the 2014 Illinois State Plumbing Code among others. That page is old enough that you should ask the Building Division which editions it enforces today. The zoning permit application warns that a clearance expires 60 days after issuance if a building permit has not been issued or construction has not started. That window is short. Because the clock starts at issuance, the order and timing of the permits matter.

Rural parcels carry water-management rules that city lots do not. The county's Surface Water Management Ordinance applies in unincorporated areas and deals with stormwater detention, floodplain regulation, and construction site sediment and erosion control. Detention has been required in the county since 1976, and the current ordinance and its technical regulation were adopted August 24, 2006. The county notes that development disturbing an acre or more has been regulated by the Illinois EPA since 2003. The zoning application itself asks whether less than one acre or one acre or more of soil will be disturbed. Questions go to the Highway Department at the number above.

How rural land is taxed

Illinois law has its own definition of a farm for assessment, and it matters on acreage. Under that law, a farm is property used solely for growing crops, raising livestock and similar agricultural uses. The statute says a farm does not include property primarily used for residential purposes, even if some farm products are grown or animals are bred on it. Farm dwellings and the parcels they sit on are assessed as part of the farm, and a farm dwelling and the tract it sits on are assessed at 33 1/3 percent of fair cash value. Farmland is valued under a separate set of sections when it has been used as a farm for the two preceding years.

Under that language, keeping a few animals does not by itself make a residential parcel a farm. Ask the Supervisor of Assessments how a specific parcel is classified, and read how a Rockford-area property tax bill is built to see how the assessed value turns into a bill. The county also keeps a form for combining parcel numbers when two adjoining parcels are merged into one, and it processes combinations only after the second installment of taxes is paid.

Bottom Line

Buying acreage in unincorporated Winnebago County is a matter of sequence. Confirm that the county, and not a village, is the zoning authority. Learn which Section 7.7.2 route the parcel qualifies under, because the quarter-quarter rule and the June 24, 1982 date decide how many houses it can hold. Verify the septic and well with the Health Department before you rely on a plan, and confirm the road and driveway permit with the Highway Department. Treat the 60-day zoning clearance as a clock, not a formality.

Ask each office for its answer in writing, because a listing sheet does not bind the county. When you are ready to compare parcels, start from the current land for sale in Rockford listings and bring the PIN to Planning and Zoning before you make an offer. This article explains what the rules say. It is not legal, tax or financial advice, and the county offices named here confirm how a rule applies to a particular parcel.

A few direct answers on the rules above, in the order you are likely to meet them.

Frequently Asked Questions