Chicago ADU Permitting Made Simple

Professional help for Chicago homeowners and developers navigating the city's ADU requirements and zoning rules.

2,664,452 residents · 607 km²

Building Code

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Local Authority

Chicago’s 2023 ADU ordinance (Section 16‑30‑040) allows accessory units in many residential districts, but the City of Chicago Department of Buildings requires a complete set of documents before a permit is issued. Missing details such as setback measurements or energy compliance can add weeks to the schedule. Our team knows the exact expectations of the Chicago Plan Review Board and can assemble a package that meets every municipal checkpoint, from site plan to structural calculations.

Required Permit Sheets for a Chicago ADU

A complete ADU submission includes a site plan that must show property lines, setbacks, existing structures, and parking if required. The floor plan should detail room dimensions, door locations, and required egress. Exterior elevations need to reflect façade materials, window sizes, and roof pitch, while sections illustrate vertical relationships and stair runs. An electrical single‑line diagram is required to demonstrate load calculations and panel locations, and Title 24 energy compliance must be demonstrated with a heating‑cooling analysis. Structural calculations verify load paths, and when the lot is on fill or has a history of settlement, a soils report is mandatory.

Chicago typically reviews complete packages within 10‑14 business days, but a pre‑application meeting with the Plan Review Board can shorten that window. Submissions must be uploaded through the City’s online portal, and any missing sheet will trigger an automatic request for clarification, extending the timeline.

Common Project Types

Detached ADU

Standalone accessory dwelling on a separate lot or backyard, meeting Chicago setback rules.

Attached ADU

Unit sharing a wall with the primary residence, designed to match existing exterior aesthetics.

Garage Conversion

Transform an existing garage into a legal ADU while complying with fire‑code egress.

Junior ADU

Smaller unit under 500 square feet, ideal for multigenerational families in Chicago.

Building Department

Authority: Chicago Department of Buildings
Address: 1220 S. Michigan Avenue, Chicago
Permit Portal: ePlan Chicago
Fees: Fees are based on project size and scope; a detailed estimate is provided after review.

Frequently Asked Questions

How long does the Chicago ADU permit process usually take?

When all required sheets are submitted correctly, the City of Chicago typically issues a decision within two weeks. Scheduling a pre‑application meeting can reduce that time, while incomplete packages may add several weeks of back‑and‑forth.

Do I need a soils report for every ADU in Chicago?

A soils report is required only when the lot is on fill, has a history of settlement, or when the building code cites unstable ground conditions. The Plan Review Board will request one if the site plan indicates potential issues.

Can I submit the permit package myself or do I need a professional?

Homeowners may submit directly through ePlan Chicago, but the city expects precise drawings and calculations. Using a professional service helps avoid common errors that trigger delays, ensuring the package meets every ordinance requirement.

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Nearby Cities

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