Subdivision Development in Kendall County, Illinois

Why Kendall County specifically: the growth numbers

Kendall County isn't just growing -- it's grown faster than any other county in Illinois for two separate decades running. 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: population climbed 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 (Grundy County, the next-closest, grew at roughly 0.58% over the same period). That's not a one-time census anomaly -- it's a two-decade pattern showing up again in current local reporting.

The current evidence is concrete and dated, not projected. Oswego, the county's largest village, has grown 154% since 2000 to an estimated 35,850-plus residents, and in 2024 was reviewing a developer's concept plan for more than 600 housing units (a mix of single-family homes, for-sale and rental townhouses, and apartments) on 160 acres along the Wolf's Crossing corridor -- part of a broader pipeline of more than 1,100 new homesites proposed for that corridor alone, equal to roughly 10% of Oswego's existing housing stock. Yorkville, the county seat, added an estimated $149 million in new construction value in 2024 alone, with 255 new housing starts (206 single-family, 48 multi-family) and more than 2,500 new housing units built over the prior 12 years, led by the Grande Reserve subdivision.

The Agricultural Allocation cap: the mechanism that actually gates new farmland houses

Before evaluating any specific parcel currently zoned A-1 Agricultural for its subdivision or new-home potential, understand the county's Agricultural Allocation program. Kendall County's Planning, Building & Zoning Department (PBZ) registers a limited running inventory of Agricultural Allocations -- essentially a rationed right to a single-family building permit on agriculturally zoned land -- generally at a rate of one home per 40 acres, with some exceptions the county allows for historical development patterns or physical site conditions that already limit a parcel's ability to be farmed. This means a smaller agricultural parcel (say, 10 or 20 acres) is not guaranteed to come with the right to build a house on it just because it's zoned A-1; that right depends on whether an allocation happens to be available for that specific tract.

For anyone evaluating land specifically for subdivision potential -- whether a small-scale developer or a buyer hoping to eventually split a larger parcel -- this changes the math. A large agricultural tract's subdivision potential isn't simply a function of its acreage and the zoning map; it's gated by whether PBZ has allocations available and whether the county's Land Resource Management Plan (LRMP), maintained by the Kendall County Regional Plan Commission (KCRPC), identifies that specific area as suited for the kind of development you're planning. Before making an offer with subdivision in mind, get a direct answer from PBZ on (a) current Agricultural Allocation availability for the parcel, (b) whether the LRMP's township-level policy for that area supports residential conversion, and (c) whether annexation by a nearby municipality (which would move the parcel out of county zoning entirely) is a live possibility.

What actual rezoning and annexation look like near the growth corridors

The Oswego and Yorkville examples above didn't happen through the Agricultural Allocation process at all -- they happened because the underlying land was annexed into the village and rezoned under the village's own zoning code, which supersedes county zoning entirely once annexation is complete. That's the practical path most large-scale subdivision development actually takes in Kendall County: a developer options agricultural land near a growing village, petitions for annexation, and works through the village's own planning and zoning process rather than the county's. If your interest in a parcel is specifically as a future subdivision play, its distance from an annexation-receptive municipality's boundary, and that municipality's own comprehensive plan for the area, generally matters more than the parcel's current county zoning designation.

That said, land that stays unincorporated and subject to county zoning still goes through the county's own Subdivision Control Ordinance, administered alongside the Zoning Ordinance by PBZ with review from the KCRPC. Whether your plan involves annexation or stays entirely within county jurisdiction, the Regional Plan Commission is the practical first stop for understanding what level of subdivision (from a simple lot split to a full platted subdivision) your parcel could support and what infrastructure requirements (roads, drainage, utility extension) would apply.

What to verify before buying with subdivision potential in mind

• Confirm current Agricultural Allocation availability for the specific parcel with PBZ -- A-1 zoning alone does not guarantee the right to build a new single-family home on a smaller tract.
• Ask PBZ and the KCRPC whether the parcel's township is designated in the Land Resource Management Plan (LRMP) for residential, agricultural-preservation, or mixed future use.
• If your plan depends on annexation into a nearby municipality (the path most large subdivisions in Kendall County actually take), contact that municipality's own planning department directly -- its comprehensive plan and zoning code, not the county's, would govern once annexed.
• Check for any pending rezoning or subdivision concept-plan applications near the parcel through PBZ or the relevant municipality's planning agenda, since active development pipelines (like the Wolf's Crossing corridor in Oswego) can materially change a parcel's near-term value and use.
• Confirm road access, utility extension costs, and septic/well feasibility independently of zoning approval -- especially for parcels farther from an existing subdivision, where infrastructure costs can be the real constraint on development potential.