Second floor landing in light building.

How Much Does It Cost To Add A Second Story To A House?

Emma Tomsich7-minute read
UPDATED: May 23, 2023

Some homeowners who live in a single-story house may consider adding a second floor to increase the size of their home. This can be done for many reasons, from accommodating a growing family to increasing the value of the home or simply wanting more space.

Doubling the size of your home’s square footage can be a tempting thought, but it does come with a price. Adding a second story addition is a bigger investment and challenge than a lot of people might realize when going into it.

Because a second-story addition is such a huge project, it’s good to have a clear sense of the process and the costs involved before making the choice to do it. Let’s take a deeper look at the realities of adding a second story to your home and what impact it can have on your life and your finances.

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Can You Add A Second Story To A House?

We’ll give you the short answer first: yes, you can usually add a second story to a house. However, there are many factors to take into consideration before beginning a second-story addition. Not every house is equipped for vertical expansion. To confirm that you can add a second story to your house, you’ll need to get a permit approved to build. You’ll also want to familiarize yourself with what barriers may present themselves with a project like this and get a clear understanding of the price before starting the remodel.

Average Cost To Add A Second Story

First things first: You’re going to want to know how much the full project will cost you before committing to anything.

The average cost of adding a second story to a house ranges from $80,000 to $600,000 total, or $100 to $300 per square foot, according to HomeAdvisor.

Full Addition Cost

A full addition creates an entire second floor of the home, removing the entire roof and building on the full size of the home. The average cost of adding a full second story to your home ranges from $100,000 to $600,000 or more.

Partial Addition Cost

Usually a lower cost, a partial addition creates a smaller second floor area, that only builds on a portion of the home. The average cost of adding a partial second-story addition to your home ranges from $80,000 to $250,000.

Additional Room Cost

The average cost of adding a bonus room second-story addition is $50,000 or more.

Second-Story Addition Cost Factors

While the foundation of your home is already there and intact, you’ll need to have it inspected to make sure it can hold the extra weight of a second floor. Certain types of soil can only stand up to a specific weight load, so you don’t want to overburden the ground and risk damage to your house or create unsafe conditions. Any contractor will make sure this is the first step in the project, which will require a structural engineer to inspect the foundation and make recommendations. Keep in mind that most foundation work for additions, if required, can cost upward of $5,000.

Additionally, the following are other expenses to factor into your remodel.


The size of your current home will impact the overall cost of adding a second story because more square footage will require more materials and labor. For example, it will cost more to add a full second-story addition onto a 2,500-square-foot, single-story home than adding one above a 1,000-square-foot home. Unique home shapes and features will also increase the overall cost of adding a second story since it involves more complex work.


The state or city you live in will also influence the overall cost of your second story addition. Environmental factors may require additional features, like heat or air conditioning. The cost for permits will also depend on where you live – and so might the cost and availability of local contractors. It will likely be easier to find but cost more to hire a contractor in a busy metropolitan area than it would in a rural location.

General Contractor And Other Professionals

You’ll likely need the help of a few professionals who can ensure safety ad style. Depending on your skill level and your plans for the space, you may need to hire a structural engineer, general contractor, architect and interior designer. The cost of these professionals will vary based on where you live but cost up to $250 per hour on average.


The materials used in your remodel will typically equate to around half of the project’s total cost. The materials and quantities needed will depend on the size of your addition, as well as how you’ll use the space. For example, if you’re going to have a kitchen or bathroom, you may need install plumbing. The quality of finish on your materials will also contribute to the overall project cost. For example, subway tile may cost less than marble and laminate floors may be less expensive than white oak flooring.


As stated before, the cost of building permits for your second story addition will likely depend on where you live and typically range from $1,200 to $2,000. Your general contractor will help you obtain the necessary permits required for your remodel.


Demolition is also a factor that contributes to the overall cost of adding a second story. Depending on the scope of your remodel, demolition can have a small or large impact on your overall budget.

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Adding A Second Story Yourself Vs. Hiring A Contractor: Cost Comparison

When it comes to home improvement projects, many renovations and remodeling projects can be less expensive to complete yourself because you aren’t paying for labor. However, based on the difficulty and length of the project, building code requirements and resources involved when adding a second story to a house, we suggest that a second-story addition is a DIY project to avoid.

Though hiring a contractor may be an expense you’d like to avoid, a contractor will be sure to keep the project on track, on budget and, most importantly, safe. In the grand scheme of things, hiring a contractor is recommended and may certainly be worth it.

The Cost Of Building Up Vs. Building Out

As you begin planning your home renovation, it’s important to compare building a second story to expanding your first story. There are many benefits to building up as well as building out. In most cases, building out can be significantly less expensive than building up. When adding a second story to their homes, many homeowners may need to pay additional costs. These added expenses can include the addition of a staircase, structural supports and footings, building permits, repairs to the first floor, architectural and structural engineering, plumbing, new HVAC, removing and storing personal items during the renovation and cost of rent or a hotel while the second floor is being built. One of the bigger problems when building out instead of up is that you may have a lack of land available.

As a homeowner, you can save money on these expenses by building out, if you can, or by renovating your lower level or basement. Additionally, it might be most cost-effective for some homeowners to sell their home and look for a house with an existing second story instead of renovating their current home.

How To Reduce Your Second Story Addition Costs

Luckily, there are a few ways you can reduce the cost of your second story addition. First, cut costs by choosing a simple layout and opting for affordable materials and furnishings. Additionally, you can save on costs by tackling some of the easy renovation steps on your own. For example, you can do interior or exterior painting, or even lay down the flooring as a DIY project.

Also, remember that you don’t have to take on the entire expense at once. Your initial investment can be for the basic structure of the second floor and the roof to make sure you can inhabit the first floor. After that, you can stretch out the finishes you add to each room on the second floor according to your budget and timeline.

Frequently Asked Questions

As you decide whether to add a second floor to your home, review these important questions to ask yourself and your contractor before beginning a second-story addition.

Why does it cost more to build a second story than a first story?

It can cost more to build a second-story addition than one on the first floor because a second-story addition typically requires that the home’s existing roof be completely removed and maybe even replaced. Depending on the condition of your existing roof, you might be able to lift it off in one or two sections with a crane and reinstall it on top of the new addition. It’s expensive to rent a crane, but not nearly as expensive as paying for an entirely new roof. Additionally, more support structures may need to be installed to ensure the second story is stable and connected to the first floor. Depending on the project, you may also need to relocate during the build, which can be costly if you decide to stay in a hotel or other rental.

Can I live in my house during the renovation?

In some cases, you can keep living in your home during a second-story addition. We’d suggest that you live elsewhere for the time being to stay safe and ensure the project is completed in a timely manner. Finding a temporary living solution will protect you and your family from dust and other moving materials while allowing the builders to keep the project on schedule.

How long does it take to build a second story?

There are many factors that may impact the length of a second story build, such as weather conditions and availability of materials. But ideally, it should take 6 – 12 months on average to complete a second-story addition. A partial addition will likely take 3 – 5 months.

How do I know if I can add a second story within my zoning code?

Visit your local government zoning office to find out if you are permitted to add a second story to your home. Many zoning codes have a limit for the height of a structure. A good rule of thumb is that if other houses near you have second stories, you should be able to build that high as well, but it’s best to check before beginning a project.

How do I find a good contractor?

You can find good contractors in any area, but before hiring one, make sure they have proper licensing and certification in remodeling and construction. A good contractor will take the time to discuss the project with you in detail and gain a deep understanding of your needs and expectations. They should also be upfront with you about pricing and not tack on any hidden costs.

The Bottom Line: Is Building A Second Story Worth It?

At the end of the day, the decision to build a second story all depends on your budget. Luckily, there are more affordable home addition options, as well as ways to save on your second-story addition. If you’re interested in learning more about financing home improvements, learn how a cash-out refinance works.

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Emma Tomsich

Emma Tomsich is a student at Marquette University studying Corporate Communications, Marketing and Public Relations. She has a passion for writing, and hopes to one day own her own business. In her free time, Emma likes to travel, shop, run and drink coffee.