Buying Land in Kendall County, Illinois

A zoning code built around one home per 40 acres on farmland

Kendall County's Zoning Ordinance -- Chapter 36 of the county code -- is administered by the Planning, Building & Zoning Department (PBZ), based at the Kendall County Courthouse, 807 John Street in Yorkville. It covers unincorporated Kendall County and, notably, the incorporated villages of Millbrook and Plattville as well, since those villages don't operate separate zoning departments. Any new addition to unincorporated Kendall County is automatically classified into the A-1 Agricultural District unless and until the County Board designates a different use, and the county maintains a Land Resource Management Plan (LRMP), developed and periodically revised by the Kendall County Regional Plan Commission (KCRPC), that guides where different kinds of development are expected township by township.

The specific mechanic that sets Kendall apart: PBZ registers a running inventory of 'Agricultural Allocations,' which are the county's way of rationing single-family building permits on A-1 Agricultural land. In general, one home is allowed for each 40 acres within an agriculturally zoned parcel, though the county provides some exceptions to accommodate historical development patterns and physical site conditions that already limit a parcel's ability to be farmed. Practically, this means a 20-acre parcel currently zoned A-1 may not automatically come with the right to build a house on it -- that right depends on whether an allocation is available for that specific tract, a fact you need to confirm with PBZ directly rather than assume from acreage alone.

Kendall County has 9 townships -- Oswego, Bristol, and Little Rock in the north (originally part of Kane County), and NaAuSay, Kendall, Fox, Big Grove, Lisbon, and Seward in the south (originally part of LaSalle County) -- each with the standard elected town-board structure. Because the county has adopted countywide zoning, Illinois's Article 110 township zoning authority does not independently apply in any of them; PBZ and the County Board are the operative zoning authority everywhere outside a municipality's own corporate limits.

Growth pressure that is current, not historical

Kendall County isn't growing quietly. It was the single fastest-growing county in the entire United States between 2000 and 2010, and it remains the fastest-growing county in Illinois today, with population climbing from 131,869 at the 2020 census to an estimated 143,000-146,000 by 2024-2025 -- an annualized rate of roughly 1.86%, ahead of every other Illinois county. Oswego, the county's largest village, has grown 154% since 2000 to an estimated 35,850-plus residents, and as of 2024 was reviewing concept plans for a 600-unit subdivision (125 single-family homes, for-sale and rental townhouses, and apartments) on 160 acres along the Wolf's Crossing corridor -- part of a broader pattern of more than 1,100 new homesites proposed for that corridor alone. Yorkville, the county seat, added roughly $149 million in new construction value in 2024, with 255 new housing starts and more than 2,500 new housing units built over the prior 12 years, led by the Grande Reserve subdivision.

For a land buyer, this cuts in a specific direction: Kendall County land near Oswego, Yorkville, or Plano is being actively evaluated for annexation and subdivision by developers right now, not hypothetically. If your goal is farmland preservation or long-term agricultural use, ask PBZ directly about your parcel's proximity to any pending annexation petition or subdivision concept plan -- a parcel two miles from an active development corridor faces a different multi-year outlook than one deep in a southern township like Lisbon or Seward. See our dedicated subdivision-development page for the specific growth data and what it means for a purchase.

Septic, GIS, and other departments to know

The Kendall County Health Department (811 W. John St, Yorkville; (630) 553-8026) issues private sewage disposal permits under the statewide IDPH Title 77 Part 905 standard, with published fees around $300 for a new installation, $200 for a replacement, and $75 for a repair -- confirm current fees before budgeting. The Kendall County GIS Viewer (maps.co.kendall.il.us/mapviewer) provides parcel and zoning-layer mapping; the Supervisor of Assessments office (504 S. Main St, Yorkville; (630) 553-4146) handles property assessment; and the Kendall County Recorder (502 S. Main St, Yorkville; (630) 553-4112) holds deed, easement, and plat records for a specific parcel.