ADU Pass
Chatham
ADU Pass helps homeowners in Chatham, Sangamon County, Illinois navigate the permit paperwork for building an accessory dwelling unit. This area covers 1 ZIP code.
Map
Sangamon County — county ADU rules and overlays
County ADU ordinance
Sangamon County (state-capital county; ~196,000 residents — central Illinois — encompassing Springfield, Chatham, Rochester, Riverton, Sherman, Auburn, Dawson, Pleasant Plains, Mechanicsburg, and unincorporated tracts across the Sangamon River prairie) regulates land use in unincorporated areas through the Sangamon County Zoning Ordinance, administered by the Sangamon County Department of Public Health Environmental Division (which administers zoning and septic) and the Sangamon County Building and Zoning Department. Illinois has no statewide ADU preemption — Illinois's stateAduLaw is netEffect 'no-statewide-law' — and is generally a home-rule state where municipalities of population 25,000+ have broad zoning authority. The Sangamon County zoning ordinance permits 'accessory living quarters' / 'accessory dwellings' in agricultural and large-lot residential districts (A, R-1, R-2) by right on parcels of typically 1+ acres subject to size limits (commonly 1,000 sq ft or 50% of principal dwelling), one-per-lot limit, and parking. Smaller residential districts treat ADUs as conditional uses requiring Zoning Board of Appeals approval.
County regulatory overlays
Illinois state — ADU law and programs
State financing programs
Illinois does not operate an ADU-specific statewide loan, grant, or forgivable-loan program. The Illinois Housing Development Authority (IHDA) is the state's housing finance agency and administers a robust portfolio of homebuyer products: Access Forgivable, Access Deferred, Access Repayable down-payment-assistance variants, the IHDA Mortgage first-mortgage product, and the federal Low-Income Housing Tax Credit allocation. The 2025 IHDA Access Home program offers DPA equal to 6% of purchase price up to $15,000. None target ADU construction directly; an ADU-bearing primary residence on an Illinois lot can qualify for the underlying mortgage when other criteria are met.
Federal (United States) — ADU-relevant rules and programs
Federal ADU law
The United States has no federal statute that directly regulates accessory dwelling unit entitlement or design. Land-use authority over ADUs resides with states and local governments under the traditional police power. Federal engagement is limited to financing (Fannie/Freddie/FHA/VA/USDA), flood insurance (FEMA/NFIP), and discretionary housing programs (HUD), which are recorded in sibling sections of this file.
Federal financing programs
Federal housing-finance agencies and GSEs set nationwide underwriting rules that govern whether an ADU can be financed, appraised, and counted toward mortgage qualifying income. The relevant actors are Fannie Mae, Freddie Mac, FHA (HUD), VA, and USDA Rural Development.
Federal tax credits
There is no ADU-specific federal tax credit. ADUs may incidentally qualify for existing federal energy-efficiency and clean-energy tax credits when the ADU construction includes qualifying measures.
Federal housing programs
HUD administers several discretionary programs that can fund ADU-related activity at the grantee's election, but none is an ADU-specific program.
ZIP Code
- 62629
Post Office
- 111 E Walnut St, 62629