Accessory Structures in Naperville, IL (2026)
9 verified accessory structures rules for Naperville, Illinois, sourced directly from the municipal code and official government pages.
Verified from official government sources
ADU Rules
Naperville regulates accessory structures under Title 6, Section 6-2-10 (Zoning). Accessory dwelling units are subject to zoning district restrictions including lot coverage, height, and setback requirements. Building permits are required for all accessory structures.
Naperville ADU & Accessory Dwelling Rules
Some RestrictionsADU Permits
Naperville's Zoning Ordinance (Title 6 of the Municipal Code) does not define 'accessory dwelling unit' as a permitted use category. A second self-contained dwelling on a single-family lot is generally allowed only where the underlying district permits two-family or multi-family use (R2 or higher), or where the Planning and Zoning Commission and City Council approve a variance, conditional use, or planned unit development. Illinois has no statewide ADU preemption statute; under the Illinois Municipal Code (65 ILCS 5/) and home-rule authority (Ill. Const. Art. VII Sec. 6), Naperville retains full zoning discretion and has historically applied it strictly.
Naperville ADU Permits (Title 6 Zoning + Illinois Building Code)
Heavy RestrictionsADU Impact Fees
Naperville imposes one of Illinois's best-known development exactions through its land-cash donation ordinance (originally Ord. 72-20, upheld in Krughoff v. City of Naperville, 354 N.E.2d 489 (Ill. App. 1976), aff'd 68 Ill. 2d 352), now codified through Title 7 subdivision and Title 10 administrative fee provisions. New residential subdivisions must dedicate land (8.6 acres per 1,000 projected residents under the 2001 amendment) or pay cash in lieu for schools and parks. Impact fees on a single ADU added to an existing lot are typically limited to building permit and utility connection charges; the land-cash exaction applies primarily at subdivision approval, not at individual building permit.
Naperville ADU Impact Fees (Land-Cash Donation Ordinance + Permit Fees)
Some RestrictionsADU Owner Occupancy
Naperville's Zoning Ordinance Title 6 does not contain an explicit owner-occupancy definition for accessory dwellings because 'ADU' is not a defined use category. Where a second dwelling has been approved through a variance or conditional use, the Planning and Zoning Commission and City Council may attach an owner-occupancy condition. Illinois has no statewide preemption of municipal owner-occupancy rules; home-rule authority under Article VII Section 6 of the Illinois Constitution preserves Naperville's discretion. Naperville's short-term rental ban (Title 3 Chapter 18) compounds these limits.
Naperville ADU Owner-Occupancy (No Codified Rule; PZC Conditions in Practice)
Some RestrictionsADU Rental Restrictions
Naperville bans short-term residential rentals citywide under Title 3 Chapter 18 of the Municipal Code (added by Ordinance 20-087, effective September 1, 2020). Stays under 30 days for compensation are unlawful regardless of platform (Airbnb, Vrbo, Booking.com). Long-term rentals (30 days or more) of accessory dwelling units are allowed where the underlying zoning permits two-family or higher use and any PZC conditions are satisfied; landlords should register with Naperville Finance for utility handling. Tenancies are governed by the Illinois Landlord and Tenant Act (765 ILCS 705/) and the Security Deposit Return Act (765 ILCS 710/). Illinois prohibits rent control under 50 ILCS 825/.
Naperville ADU Rental Rules (Long-Term Only; STR Banned Under Title 3 Ch. 18)
Heavy RestrictionsShed Rules
Naperville requires building permits for sheds and accessory outbuildings. Sheds must comply with zoning setbacks, lot coverage limits, and height restrictions under Title 6. All construction projects including accessory outbuildings require permits.
Naperville Shed Rules & Permits
Some RestrictionsGarage Conversions
Naperville requires building permits for garage conversions. Converting a garage to living space must comply with building codes, zoning requirements for off-street parking replacement, and residential occupancy standards under the 2018 IRC.
Naperville Garage Conversion Rules
Some RestrictionsCarport Rules
Naperville requires building permits for carports as accessory structures under Title 6, Section 6-2-10. Carports must comply with setback requirements, lot coverage limits, and height restrictions. They count toward the maximum impervious surface on the lot.
Naperville Carport Permit & Zoning Rules
Some RestrictionsTiny Homes
Naperville does not have specific tiny home provisions. Tiny homes on foundations must meet minimum dwelling standards under the 2018 IRC as adopted by the city. Tiny homes on wheels are classified as vehicles/trailers and subject to parking and storage restrictions.
Naperville Tiny Home Zoning Rules
Some RestrictionsLooking for DuPage County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Naperville city rules.
Accessory Structures in DuPage County →