Home Addition Cost in Chicago [2025 Data]

 Building an addition to your Chicago home costs an average of $66,735, with most homeowners paying from $29,051 to $106,437. The cost of an addition can vary widely based on the size and type of the addition, whether you’re building up to another story or out on ground level, what materials you choose, and more. We explore some of the things that determine how much you’ll pay for a home addition in Chicago.

Home Addition Cost Factors 

The cost to build a home addition in Chicago, IL, is based on factors like the size and type of the addition, labor costs, permit fees, and more. Take a look at how these factors can affect the total project price so you can budget for your new addition. 

Size

Home additions cost between $80 and $300 per square foot if you’re building out and between $300 and $700 per square foot if you’re building up. The cost to add a 10x10 room to a house costs an average of about $18,000 if you build out and around $52,000 if you build up. Chicago’s average lot size is relatively small at around 1,700 square feet, which means that many additions will need to be built up onto another story rather than built as a bump-out at ground level.

Where in those ranges your total falls also depends on the complexity of the room and its finishes. For example, adding a bathroom will often cost more than a bedroom since it requires additional plumbing and electrical work.

Materials

As you can imagine, it takes many kinds of building materials to complete a custom home addition. Material prices vary widely, so your price could push closer to $106,437 if you choose luxury or high-end materials at each step of the way.

Framing Materials Cost:

Insulation Materials Cost:

Roofing Materials Cost:

Flooring Materials Cost:

Siding Materials Cost

Type

The cost to add on a room varies based on the size and type of the home addition. Rooms like kitchens and bathrooms require plumbing work that a bedroom doesn’t, while an unfinished attic home addition may not require electrical or HVAC work that a bedroom needs. The cost per square foot for your home addition will vary based on utilities and the finishes required for how you plan on using the extra square footage.

Site Prep

On average, site prep for a home addition costs between $1,500 and $5,000. You may not need any site prep in some cases, while other home addition projects may require grading land, demolishing concrete patios, removing trees, and other work that can add to your total.

Permits

In Chicago, you’ll need to get a permit to build an addition before starting to build. Permit fees will depend on the size of the addition, and you’ll need to obtain all applicable permits for your addition and pay any necessary fees before beginning work. If you’re working with a home builder or general contractor, confirm that permits are in place—as the homeowner, you’re ultimately responsible for making sure the work is properly permitted. 

Home Addition Pro Costs

Home Builder Pro Costs

Hiring a homebuilder in Chicago, IL, to build your addition will cost an average, or 10% to 20% of the total project cost. In general, around half of your project budget will be spent on labor costs in total for the various pros who will be working on your addition. 

A qualified homebuilder or general contractor will answer all your home addition questions, coordinate the schedule and subcontractors, keep you on budget, and even shorten how long your addition takes to build by addressing any problems that come up during the build. 

Additional Pros to Consider Hiring

Building an addition can require the help of some additional pros. In most cases, you’ll need pros to run utilities, add a roof, and perform finish work like painting. You’ll also want a structural engineer to sign off on your building plans to be sure everything is structurally sound and code-compliant. 

• Interior painter cost: $2–$6 per sq. ft.

• Roofer cost: $4–$11 per sq. ft.

• Electrician cost: $50–$100 per hour

• HVAC technician cost: $100–$250 per hour

• Plumber cost: $45–$200 per hour

• Carpenter cost: $75–$125 per hour

• Structural engineer cost: $200–$1,500

• Landscaper cost: $1,200–$6,200

Does a Home Addition Increase Property Value?

A home addition can add value to your home with a return on investment (ROI) of 20% to 50%, depending on the type of addition. In Chicago, adding a bathroom or a primary suite offers a high ROI and can make your home more competitive against similar properties when it comes time to sell, since space in Chicago homes can be limited due to the city’s smaller average lot size. 

How Angi Gets Its Cost Data

Home is the most important place on earth, which is why Angi has helped more than 150 million homeowners transform their houses into homes they adore. To help homeowners with their next project, Angi provides readers with the most accurate cost data and upholds strict editorial standards. We survey real Angi customers about their project costs to develop the pricing data you see, so you can make the best decisions for you and your home. We pair this data with research from reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects. 

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