Home Addition Cost in Indianapolis [2025 Data]

A home addition in Indianapolis costs an average of $24,418, and most projects in the city total between $7,730 and $45,278. Your costs will depend mostly on the size of the addition and whether you plan to build out or build a second story to add square footage. Most home addition projects in Indianapolis are relatively small and involve budget-friendly materials, which helps keep costs well below the national average.

Home Addition Cost Factors 

Building a home addition in Indianapolis, Indiana, can cost anywhere from $1,500 up to $80,000. The type of home addition, the square footage, the type of room you’re adding, and the quality of the materials you choose will mostly account for differences in pricing.

Size

Home additions cost between $40 and $100 per square foot if you’re building out and between $150 and $250 per square foot if you’re building up. The cost to add a 10x10 room to a home in Indianapolis costs around $7,000 if you build out and $20,000 if you build up.

The average plot in Indianapolis is 0.193 acres or right around 8,400 square feet, and the average home size in the city is 1,700 square feet. That means that most residents will have plenty of room—an average of 80% of their total lot size—to build out instead of up to save money. This is one key reason why home addition costs in Indianapolis are well below the national average.

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 $45,278 if you choose luxury or high-end materials at each step of the way. Prices can push up to $80,000 if you go with the most luxurious materials, but these high-end upgrades will be out of place unless you live in a more expensive neighborhood, like Zionsville, Castleton, or Meridian Hills.

When adding to your home, you’ll almost always need exterior materials, but the interior materials will depend on the type of room you’re adding. In the tables below, we’ll include some standard exterior materials that stand up well to the above-average rainfall, hot, sunny summers, and relatively cold winters. Note that interior materials will also range widely in cost, but these are based more on personal preference rather than the local climate.

Foundation Materials Cost:

Insulation Materials Cost:

Roofing Materials Cost:

Siding Materials Cost:

Window Frame Materials Cost:

Type

The cost to add on a room varies based on the type of home addition you want and the type of room you’re building. 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.

Thanks to the above-average property sizes in Indianapolis, most residents have the option of going the more affordable route of building out rather than building up, as the average home takes up just 20% of the plot it’s on. As such, more homeowners in the city will build out, meaning they’re more likely to need site preparation that drives up costs. Still, this will be more affordable than paying to build up for your home addition.

Permits

The City of Indianapolis requires building permits for home additions, so this project will always require permits. The city charges flat fees for additional structures for single-family residences, so you should budget for a $32 application fee plus a $108 permit fee, putting your total at $140. If you’re adding onto a multi-family residence, your permit fee will be $714 if you’re adding a new unit.

Home Addition Pro Costs

Hiring a homebuilder in Indianapolis means paying an average of between $9,700 and $14,700 for labor alone, which accounts for between 40% and 60% of your total. This is just slightly higher than the national average, as the local cost of living is between 1% and 2% higher than in most other cities.

You’ll also need to budget for sales tax, which comes at a rate of 7% in Indianapolis, including state and city taxes. Given the average home addition cost in the city, you’re looking at an average sales tax of $1,709.

Does a Home Addition Increase Property Value?

Yes, a home addition will increase your property value in Indianapolis. The average return on investment (ROI) for a home addition is between 20% and 50%, which means the average project in Indianapolis will add between $4,900 and $12,200 to your home value. With average real estate prices in the city sitting at $250,000, that’s between a 2% and 5% bump in actual property value.

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. 

Want to help us improve our cost data? Send us a recent project quote to [email protected]. Quotes and personal information will not be shared publicly.