The short answer
Designing a 500 square foot addition with a Chicago architect costs about $3,600 to $9,000, and a full set for a 2,500 square foot new home about $15,000 to $45,000. Illinois law lets you skip an architect for a detached house, but the City of Chicago accepts plan-based permits only from an Illinois-licensed architect or engineer, so most city projects need one anyway.
What architects charge in Chicago
Our ranges start from national fee data and apply Chicago's construction cost factor of 1.2 from the U.S. Army Corps of Engineers Area Cost Factors. Design fees and building costs are listed separately, because the architect is usually paid months before the first contractor shows up.
| Job | Chicago (typical range) | US average |
|---|---|---|
| Architect fees, ADU (600 sq ft) | $5,750–$12,950 | $4,800–$10,800 |
| Architect fees, addition (500 sq ft) | $3,600–$9,000 | $3,000–$7,500 |
| Architect fees, new home (2,500 sq ft) | $15,000–$45,000 | $12,500–$37,500 |
| 3D rendering package | $960–$3,850 | $800–$3,200 |
| Prefab ADU, 600 sq ft, built | $57,600–$115,200 | $48,000–$96,000 |
| Garage conversion ADU, 600 sq ft | $36,000–$144,000 | $30,000–$120,000 |
| Attached ADU, 600 sq ft | $90,000–$162,000 | $75,000–$135,000 |
| Detached ADU, 600 sq ft | $108,000–$180,000 | $90,000–$150,000 |
| ADU above a garage, 600 sq ft | $144,000–$360,000 | $120,000–$300,000 |
| Land survey | $480–$2,150 | $400–$1,800 |
Estimates for 2026, including labor and standard parts. Chicago prices use the metro's construction cost factor of 1.20 (US average = 1.00) from the U.S. Army Corps of Engineers Area Cost Factors. Your quote depends on access, materials and the condition of the home.
The calculator estimates the design fee and the weeks to a permit for your project type and ZIP code. The architecture calculator page has a fuller version.
How the fee is usually set
HomeGuide's national survey finds residential architects charging 5% to 20% of the construction cost, $2 to $15 per square foot, or $100 to $250 an hour, with principals at up to $350 (HomeGuide). At the Chicago factor, hourly work comes to roughly $120 to $420. A permit set alone runs $2,000 to $20,000 nationally, and full service through construction $15,000 to $80,000 or more.
Most contracts split the fee by phase. Construction documents, the drawings the city reviews and the builders price, take the biggest share, about 40%. Schematic design takes about 20%, design development 10%, bidding 5% and construction administration 25%. If budget is tight, some owners hire the architect only through the permit set and handle construction themselves, which our guide to permit drawings explains.
What pushes a Chicago fee up:
- A lot in a landmark district, where the Commission on Chicago Landmarks reviews the design
- An addition or a dormer on an older brick house, where the existing structure has to be measured and checked
- A zoning problem that needs a variation or an administrative adjustment before the permit
- A coach house, which brings its own utility, fire separation and zoning questions
Do you need an architect in Illinois?
State law and city law answer this differently, and inside Chicago the city rule usually decides it.
What the state says
The Illinois Architecture Practice Act lists four cases where an architect is not required (225 ILCS 305/3):
| Exempt under state law | Still needs an architect or engineer |
|---|---|
| Building, remodeling or repairing a detached single-family house on one lot | Any multifamily building of three or more units |
| A wood-frame two-family house on one lot, up to two stories plus a basement | A two-flat of masonry, or one taller than two stories |
| Interior design work with no life safety or structural change | Interior changes that affect structure or life safety |
| Farm buildings outside city or village limits | A building whose use or occupancy changes |
The same section adds a catch: when a local ordinance requires an architect for any of the exempt buildings, the state law applies after all. Structural and professional engineers can do some of the same work under their own licensing acts.
What the City of Chicago says
Chicago's Department of Buildings requires plans by an Illinois-licensed architect or engineer for every plan-based permit, and only a licensed architect, engineer or city-licensed expediter can file the application (Chicago DOB). Small repairs and many replacements go through the online Express Permit Program with no drawings. But the Express Permit rules for interior work say that moving walls, structural changes, new stairs, exterior window or door work, and turning an attic or garage into living space all need drawings from an Illinois-licensed architect or structural engineer (Express Permit, interior alteration).
So if you are finishing an attic in a bungalow, adding a rear addition, building a dormer or opening a bearing wall in a two-flat, you need a licensed designer in the city.
In the suburbs and Northwest Indiana
Evanston, Oak Park, Naperville, Schaumburg, Aurora and Joliet each set their own submittal rules under the state code, so ask the village what it wants drawn and stamped before you hire anyone. In Indiana, the state Department of Homeland Security reviews plans for Class 1 buildings, which are those used by the public, by employees or by three or more tenants (IDHS). A house with one or two units is a Class 2 structure under Indiana law, and its permit comes from the city, town or county building department in Gary, Hammond, Valparaiso or wherever you live.
Coach houses and basement units under the 2025 ADU ordinance
For decades Chicago banned new coach houses and basement apartments. The Department of Housing says zoning changes in 1957 added parking requirements and prohibited secondary homes on a lot (Chicago DOH). A 2020 ordinance reopened the door in five pilot areas. On September 25, 2025, the City Council passed a citywide expansion, and the new rules took effect April 1, 2026 (Block Club Chicago). The mayor's office says the change roughly doubles the number of eligible parcels, from about 116,000 to about 245,000 (City of Chicago).
Where you can add a unit
ADUs are allowed by right in multi-unit residential districts and in most business and commercial districts. In single-family districts (RS-1, RS-2 and RS-3), they are allowed only inside an "ADU-Allowed RS Area," which includes the old pilot neighborhoods and any area the City Council later opts in. Some of those areas cap how many units can be approved on one block in a year:
| Zoning district | ADU pre-certifications per block per year |
|---|---|
| RS-1 | 1 |
| RS-2 | 2 |
| RS-3 | 3 |
Some RS areas also require the owner to live in the main house. Check your address on the city's ADU eligibility map before paying for design.
How many units, and what kind
The city splits ADUs into conversion units, which sit inside the existing building in a basement or attic, and coach houses, which are separate buildings in the yard. A lot with one to four existing legal units can add one conversion unit and one coach house. Bigger buildings get more conversion units (a building of 11 to 13 units can add four), but every lot is limited to one coach house (ADU requirements).
Other rules that shape the design:
- A conversion unit needs a main building at least 20 years old
- No extra parking is required for either type
- Short-term rentals are not allowed in conversion units or in coach houses built after 2021
- On a new-construction lot, the coach house can only go up after the main house
- Every second ADU on the same property must be rented at an affordable rate
- Contractors building a new coach house must take part in a U.S. Department of Labor apprenticeship program
The order of steps
- Check eligibility on the city map.
- Apply to the Department of Housing for ADU pre-certification.
- Have the architect draw the permit set.
- Apply to the Department of Buildings for the permit. Pre-certification does not guarantee approval.
A 600 square foot detached coach house runs roughly $108,000 to $180,000 to build at Chicago prices, using HomeGuide's ADU cost data at the 1.2 factor. A basement conversion inside an old brick two-flat costs less per square foot but brings ceiling height, egress windows, fire separation and sewer backup into the design. Our ADU design guide covers layout choices.
Do you need a permit?
Yes, for any addition, dormer, coach house, basement unit or new home. In Chicago every project starts with zoning approval, and then the architect picks a review track:
| Track | Who can use it | Timing |
|---|---|---|
| Standard Plan Review | Any project with architectural plans, filed through E-Plan with an assigned project manager | Depends on corrections and workload |
| Self-Certification | An Illinois-licensed architect or structural engineer who has taken the city's extra training certifies the plans | Typically issued within 10 business days of zoning approval |
| Express Permit | Repairs and small projects without structural changes | Online, no drawings |
Sources: Standard Plan Review, Self-Certification. Self-certified permits move fast only when the contractors' city licenses are valid and the building has no open violations or stop work orders, so clear those first. Not every architect is trained for Self-Certification, so ask.
For a bigger interior job that stays within the Express Permit limits, a single-unit interior alteration of up to 2,000 square feet with no change to load-bearing elements or exits carries a $500 stand-alone permit fee (fee table). Owners 65 or older who meet the income and residency rules can ask DOB to waive building permit fees on repairs, alterations and additions to buildings of one to three units.
Landmark districts
Chicago has 62 landmark districts and 388 individual landmarks. The Commission on Chicago Landmarks must approve work on those properties before the city issues a permit, and it reviewed 1,584 permit applications in 2024 (Commission annual report). Most reviews happen inside the regular permit process and many are approved in a day. Visible additions, significant alterations and demolitions go to a monthly Permit Review Committee, which adds time to the schedule.
Energy code
Inside the city, the 2022 Chicago Energy Transformation Code, based on the 2021 IECC, applies, and residential compliance can be shown with REScheck or Phius certification. New buildings need a solar-ready roof zone of at least 40% of the roof area, a conduit path to the main panel and space for a future battery (Chicago DOB). In the Illinois suburbs, the 2024 IECC as amended by the state took effect November 30, 2025. Your architect should include the energy compliance documents in the permit set.
Structural engineering
Most additions, dormers and coach houses here need a structural engineer. The Chicago Building Code designs roofs for a ground snow load of 25 pounds per square foot and requires foundations to reach at least 42 inches below grade for frost protection, which matters for a new coach house or a rear addition on its own footing. HomeGuide puts structural plans at $500 to $3,000 for an average house or remodel and up to $12,000 for large projects (HomeGuide). Our guide to structural coordination explains how those drawings fit the architect's set.
Bungalows are a common case. The Historic Chicago Bungalow Association counts more than 80,000 of them, about one-third of the city's single-family houses, typically brick, a story and a half over a full basement (Chicago Bungalow Association). Raising the half story into a full second floor means checking the existing walls and foundation before any layout is fixed.
Home additions: who builds them
In Chicago, the builder needs a city general contractor license. Class E covers projects up to $500,000 with no demolition and requires $1 million of liability insurance, and larger classes cover bigger jobs (Chicago DOB). An owner can act as their own general contractor on a primary residence of three or fewer stories and six or fewer units, for one property a year, but excavation and demolition still need licensed pros. Illinois law requires a written contract for any home repair or remodeling job over $1,000. Our additions guide covers costs and phasing.
How to check an architect before you hire
- Look up the license with the Illinois Department of Financial and Professional Regulation's License Lookup. In Indiana, use the Professional Licensing Agency's architects board.
- Ask whether the architect is trained for Chicago Self-Certification, and whether they have filed in your zoning district or landmark district before.
- Get a written contract that states the phases, the fee for each, what happens if the city asks for corrections, and who owns the drawings.
- Ask who will do the structural drawings, the energy compliance documents and the survey.
- For an ADU, ask whether they have taken a project through DOH pre-certification.
If you are not sure what to build yet, our residential design guide walks through the early phases, and 3D renderings can show a dormer or coach house from the street before you commit.
Areas we cover
GOLDGCP architects and vetted Pros work across the Chicago metro:
- Chicago, including landmark districts and ADU-Allowed areas
- Evanston
- Oak Park
- Schaumburg
- Naperville
- Aurora
- Joliet
- Northwest Indiana, including Gary, Hammond and Valparaiso
Each suburb and Indiana city runs its own building department. Enter your ZIP code to see design and building prices where you live.
How GOLDGCP works
- Tell us about the lot and what you want to build.
- Our in-house architects check zoning, ADU eligibility and landmark status, then draw the permit set.
- We match you with 3 vetted, licensed builders and show prices by ZIP code.
- You approve each stage and release milestone payments directly to the builder, tracked in the client portal. See payment protection.
Builders pass six-step vetting first: state license verification, an insurance check, a background and business check, a portfolio review, client reference calls, and onboarding with a quality score.
Frequently asked questions
How much does an architect cost in Chicago?
About $3,600 to $9,000 to design a 500 square foot addition, $5,750 to $12,950 for a 600 square foot ADU, and $15,000 to $45,000 for a 2,500 square foot new home, using HomeGuide's national data at Chicago's 1.2 cost factor. Hourly rates run about $120 to $420.
Do I need an architect to build an addition in Chicago?
Usually yes. Illinois law exempts a detached single-family house, but the City of Chicago requires plans by an Illinois-licensed architect or engineer for plan-based permits. Structural work, moved walls and attic conversions all fall outside the no-drawing Express Permit.
Can I build a coach house in Chicago?
Since April 1, 2026, coach houses are allowed by right in multi-unit, business and commercial districts. In RS single-family districts they are allowed only in ADU-Allowed areas, sometimes with block caps and owner occupancy. Check the city's map, then apply for pre-certification with the Department of Housing.
Can I add a basement apartment to my Chicago two-flat?
If the lot is eligible and the building is at least 20 years old, a building with one to four units can add one conversion unit, plus one coach house. No extra parking is required. You need DOH pre-certification and a building permit, and short-term rentals are not allowed.
How long does a Chicago building permit take?
It depends on the track. Self-certified permits are typically issued within 10 business days after zoning approval, if contractor licenses are valid and there are no open violations. Standard Plan Review takes longer and depends on corrections. Landmark projects with visible changes add a committee review.
How do I check an architect's license in Illinois?
Use the IDFPR License Lookup online, which the state treats as primary source verification. Search by name and confirm the license is active. For Northwest Indiana, check the Indiana Professional Licensing Agency's architects board.
Do I need an architect in Northwest Indiana?
For a one- or two-family house, Indiana treats the building as Class 2, and the local building department sets what drawings it wants. Buildings used by the public, employees or three or more tenants are Class 1 and go through state design release.
How we calculate these prices
GOLDGCP starts from national price ranges for each job, taken from published 2026 cost guides and checked against local price guides where they exist. To get a local price, we multiply the national range by the construction cost factor for the metro from the U.S. Army Corps of Engineers Area Cost Factors (US average = 1.00). For ZIP codes outside the 50 largest metros, the calculator uses the state's price level from the Bureau of Economic Analysis Regional Price Parities. Ranges include labor and standard materials but not unusual site conditions, so a written quote after an inspection is always the final price.
Sources
- How much does an architect cost? · HomeGuide
- Illinois Architecture Practice Act of 1989, Sec. 3 (225 ILCS 305/3) · Illinois General Assembly
- How to Apply for a Building Permit · City of Chicago Department of Buildings
- Citywide ADU Expansion press release · City of Chicago, Mayor's Office
- ADU Requirements · Chicago Department of Housing
- New Coach Houses, Basement Units To Be Allowed Citywide · Block Club Chicago
- Self-Certification Permits · City of Chicago Department of Buildings
- Commission on Chicago Landmarks 2024 Annual Report · City of Chicago
- Area Cost Factors, PAX Newsletter 3.2.1 (2024) · U.S. Army Corps of Engineers
- Regional Price Parities by State · U.S. Bureau of Economic Analysis
About this guide
Written by the GOLDGCP editorial team. Prices come from national cost guides adjusted with official construction cost factors for Chicago; rules and statistics come from the agencies and reports linked in the text. We update this page when prices or codes change.
