Home Addition Cost in Phoenix [2025 Data]

On average, homes in Phoenix, AZ, are smaller than the national average, so square footage can be at a premium. Building an addition is a great way to gain valuable square footage if your home is too small for your needs. The cost of a home addition in Phoenix averages around $42,118, and most homeowners pay between $20,088 and $66,247. We break down some of the costs associated with a home addition so you can budget accurately for this project.

Home Addition Cost Factors 

The cost of a home addition in Phoenix, AZ, depends on a range of factors, including the addition size and type, the materials used, labor costs, site prep, and more. Take a look at some of the things that affect how much you’ll pay for your home addition. 

Size

Home additions cost between $60 and $200 per square foot if you’re building out and between $200 and $500 per square foot if you’re building up. The cost to add a 10x10 room to a house costs an average of about $12,000 if you build out and around $35,000 if you build up.

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 $66,247 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 type of home addition and size of the room you’re building. Rooms like kitchens, bathrooms, and laundry room additions 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

Phoenix requires homeowners to obtain a building permit from the Department of Planning and Development before building a home addition. Permit fees are based on the type and scope of the project, so be sure to confirm with your contractor or the city that you’ve paid all necessary fees and secured the applicable permits before beginning work. Failure to obtain a permit for a home addition can lead to penalty fees, citations, and even having to remove the unpermitted work. 

Home Addition Pro Costs

Homebuilder Costs

Expect to pay about 40% to 60% of your total project costs in labor costs for various pros. Hiring an experienced general contractor or homebuilder in Phoenix, AZ, to build your addition will cost 10% to 20% of the project cost. A qualified pro can manage your project, work with subcontractors, answer your home addition questions, and keep your project on schedule. 

Additional Pros to Consider Hiring

Building a home addition involves coordinating various professionals to complete the work. In addition to a general contractor or homebuilder, you may need to hire an electrician, plumber, and HVAC tech to install utilities. You may also need to bring in a carpenter, roofer, and interior finish pros like interior painters, flooring installers, and drywall installers. A structural engineer is a must-have for an addition to ensure your plans are structurally sound. 

• 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?

Building an addition can increase your home’s value, providing a return on investment (ROI) of 20% to 50%. Phoenix’s average home size is around 1,600 square feet, compared to the national average of around 2,200 square feet, so homes with more square footage may be more attractive to potential buyers when compared to similar properties on the market. 

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.