Home Addition Costs & Value at Resale

Home additions vary in cost across the country so it's a bit scary to give you “average costs” because costs in any area can be higher or lower than the national average. In fact the yearly home Remodeling Cost vs Value Report (www.costvsvalue.com), breaks the data down for  9 regions (and 81 cities) across the USA to reflect regional differences for home additions and other remodeling projects.

Costs vary based on weather patterns, building codes that reflect weather variations, and the cost of labor and materials which fluctuate based on the cost of living for each region. In 2022, building material costs have also increased due to supply chain problems … following the Covid-19 pandemic.

Costs for Home Additions Across the US

For those who want to research remodeling costs for their region, the data below reflects US averages but you can easily find your regional data at Remodeling.com's Cost vs Value report. Here are the nine regions you'll find there:

• East coast regions – New England, Middle Atlantic (New York, New Jersey and Pennsylvania) and the South Atlantic (Delaware south to Florida).
• Southern regions – East South Central (Kentucky, Tennessee, Alabama and Mississippi) and West South Central (Arkansas, Louisiana, Oklahoma and Texas).
• Midwest regions – East North Central (Wisconsin and Illinois east to Pennsylvania) and West North Central (Dakotas south to Kansas and Minnesota south to Missouri).
• West regions – cover the Mountain states ( Montana and Idaho south to Arizona and New Mexico) and the Pacific states (Washington, Oregon and California).

But you'll want to dig deeper as there's data for each of the 9 regions, or if you register you can get data for the city nearest where you live.

Researching the Cost of Home Additions

Home additions are expensive but they also add value to your home. When planning a home addition or any of the remodeling projects included in the Cost vs Value report, you should review the data to make sure you don't over invest in a project.

For example, if you live in an area where the average home sells for $350,000, you probably want to plan one of the mid-range home additions versus an upscale home addition. This will help you get the best return on your investment (see table below) when it's time to sell your home, because your home's market (and appraised) value is based on comparable home sales.

Included below are all the job cost, resale value and percent of cost you can expect to recoup on resale …. for the home additions covered in the Cost vs Value Reports from 2022 back to 2009. You'll want to dig deeper to see the size and finishes for the additions surveyed.

Home Additions: The Cost Factors You Can Control

Home additions are made up of many different costs, most of which you can control as you define the size of your addition and the finishes that will be used. To help you get started, here are some guidelines to getting the most value for your investment:

• Home additions that build up are cheaper because you avoid excavation and foundation costs. That's why you might want to compare finishing a basement or expanding an attic to create enough living space versus a two-story addition. 
• Home additions that don't include plumbing have lower costs per square foot, because you don't have to run pipes or connect them to the existing system. To save costs for a new bathroom, place it next to (or above/below) existing plumbing, i.e. this is why you often find bathrooms stacked, one over the other … or the kitchen or laundry room.
• Home additions focus on adding living space but you don't want to go overboard. If a child's bedroom will work at 10 x 14 feet, then don't make it 12 x 16 ft which is 37% larger. It's true that as the size of the addition increases, the cost per square foot decreases but you may also have to increase your heating and/or air conditioning capacity for this added space.

Home Additions Need Good Planning

When you take time to plan your home addition, you have time to make trade-offs and save money as it's always cheaper to make changes on paper. Decide how much you can afford and set aside 10 to 20% for contingency, i.e. problems you can't forsee. This will give you time to adjust the size and scope of any home addition to fit your budget.

My experience running a handyman business was people get excited as the project moves forward and make impulsive decisions that drive many projects over budget. In frustration, customers would blame my technicians for cost overruns even though they were due to problems that had been ignored for years.

We were replacing a bathtub and the tile surround. We didn't uncover the leaky bathroom window until we removed the old wall and had to replace the window, the insulation in the wall and strengthen some of the rotted wall joists. My customer got upset when we went over budget … although now I realize, I should have split the work up into two invoices to show the cost of the unplanned work.

Job Cost & Resale Value

When updating this article, I decided to provide data for the last 11 years so you can see how prices have increased over the years, especially now with supply chain and labor problems.

Bathroom Additions

Bathroom addition costs are based on the size of the bathroom, the type of foundation supporting the room and the finishes – bathtub, toilet, vanity, countertop, lighting, etc. Homeowners can influence the cost with the size of the bathroom and the finishes they pick (click link to see a list of the features included for this addition).

Master Suite Addition

A master suite includes a bedroom, private bathroom and one or two closets. The “midrange” master suite addition reflected here includes a single closet and if you want to gasp, check out the amenities like a fireplace, in the upscale master suite addition … for a cost of $356,945.

Family Room Addition

The family room addition here is a 16 x 25 feet room with engineered wood floors, two operable skylights and a nice number of windows plus a patio door. You should spend time studying Remodeling's detailed descriptions. When I looked at the illustrations below for the family room addition, I realized there would be added costs to move and/or build a new deck as large as the old one … and you want to know these costs up front.

Two-Story Additions

This 2-story addition is 24 x 16 ft with a family room on the first floor and a bedroom with full bathroom on the second floor. The family room has a pre-fabricated gas fireplace and wood clad windows … but for all the details, just click the link below.

Other Home Additions

Remodeling's Cost vs Value surveys also cover garage, sunroom and deck additions. We haven't included the deck information here as you first need to decide if you want to use wood or composite deck material … which will affect the home addition costs.

Want more home addition tips? Here are a few articles that will help you discover if a home addition is in your future:

• Home Additions Add Needed Living Space covers the different types of home additions, from a simple bump-out to 2-story additions.
• Is Building a Garage Addition a Smart Investment? goes into more detail on how you can (should) research the home addition you want.
• Remodeling to Get Your Dream Home (click All Remodeling Articles) offers more remodeling tips to create the home you want as it's cheaper to renovate space you already have within your four walls.