Adding An Addition To A House: Costs, Ideas And FAQs

Many people reach the point where they begin to feel cramped for space in their home. As the years go by, your family starts to grow, and you add pets and belongings to the mix. If you love your home but want a little extra room, a home addition may be a good option for you.

Adding an addition to a house is a great way to add more square footage to your home while avoiding the stress of moving. But home additions can be expensive, so you want to understand the average costs before getting started.

4 Questions To Ask Before Adding An Addition To A House

Adding on to your house sounds appealing, but are you ready for this kind of commitment? The following four questions will help you determine if a home addition is the right choice for you.

1. How Much Does A Home Addition Cost?

According to Angi, the average home addition costs between $4,500 and $150,000. That’s a pretty wide range, and the costs can vary greatly depending on your location. For example, the average home addition project in Kansas City, Missouri will cost $31,535, while it would cost an average of $86,062 in San Diego, California. 

The cost will also depend on the type of addition you’re building, the size of the project, and the materials used. The bigger your home addition, the more money it will cost. And you may have to pay for additional features like laying a new foundation, adding more insulation and new electrical wiring.

Unless you’re capable of tackling the project on your own, you may also need to pay for labor costs. A carpenter, electrician and plumber are just a few of the tradespeople you may need to use to complete the project.

And if you live in an urban or suburban area, you may have to obtain a permit to ensure all building codes are met. Building codes are laws regulating the minimum requirements for structural systems and plumbing. The typical building permit costs between $460 and $2,770. 

The best thing you can do is come up with a renovation budget before attempting to begin your home addition. It’s easy to underestimate the costs of a home addition, so a budget will give you a realistic picture of what you can afford. And once you see what everything costs, it will help you determine your priorities for what’s necessary and what isn’t.

2. What Are The Pros And Cons Of A Home Addition?

A home addition lets you add square footage to your home without the stress of needing to move. The addition can make your home more functional and can even increase the resale value. For example, remodeling your kitchen, bathroom or deck can increase the home’s value substantially. 

But there’s no guarantee your home addition will provide a return on investment. And while adding an addition to your home will help you avoid moving, the process isn’t stress-free. Home renovations can disrupt your daily life for a while, and your neighbors may not enjoy the ongoing construction.

3. Should You DIY Or Hire A Contractor?

You also need to decide whether you’ll complete the project yourself or hire a professional contractor to manage it for you. And this will really depend on your current situation and experience.

For example, let’s say you’re a licensed and experienced contractor who has the time to complete the project yourself. In this scenario, there’s probably no reason for you to hire someone else. But most everyone else can benefit from hiring a contractor.

Hiring a contractor will ensure the work is done correctly and help you avoid wasting time and money. A licensed contractor can handle the project from beginning to end and will ensure you have the necessary permits and hire subcontractors to do the job.

The only real disadvantage of hiring a contractor is the cost — most contractors will charge 10% to 20% of the entire project. Getting bids from multiple contractors will help you find a qualified contractor at the right price.

4. How Do You Find A Reputable Contractor?

Hiring a contractor to manage your home addition isn’t cheap, so you want to make sure you find the right person from the start. Hiring the wrong contractor can negatively impact your home’s value if they do sloppy work. And poor project management skills can lead to delays and cause you to go over budget.

Before looking into contractors, take some time to come up with a detailed plan for your project. The more specific you can be about what you’re looking for, the easier it will be for a contractor to give you an accurate bid. You should also familiarize yourself with the current cost of labor and materials, so you have an accurate idea of what you’ll need to pay. 

From there, you can check with your network and ask for recommendations for local contractors. It’s a good idea to interview at least three contractors and ask each person for references from previous jobs they’ve completed.

You should also check to ensure that each contractor is fully licensed and bonded. Each state has different licensing requirements, so you’ll need to find out what they are where you live.

Once you’ve found the right contractor, you should have them sign a contract that outlines the scope of work, payment schedule, and materials. It should also outline a termination clause that protects everyone involved.

7 Home Addition Ideas

Are you looking for ways to spruce up your home but aren’t sure where to start? Here are seven home ideas to consider.

1. Kitchen Addition

A kitchen addition has one of the highest returns on investment.

If you don’t have much space in the kitchen, you may consider a kitchen addition. In addition to adding more square footage, you could upgrade your appliances, add stone countertops and replace your cabinets.

And a kitchen is one of the biggest selling points for home buyers, so this addition could yield a significant return on your investment. If a potential buyer loves the kitchen, they’ll often be willing to overlook other negative features in the home.

However, kitchen additions are expensive, costing anywhere between $5,000 and $125,000 with an average cost of $65,000. This high price tag is largely due to the complex electrical and plumbing requirements. 

2. Sunroom Addition

A sunroom can be an enjoyable addition to your home.

A sunroom allows you to enjoy nature without having to deal with bugs, wind and other unpleasant elements. The cost of a sunroom addition isn’t cheap, though the exact cost will vary depending on the type of addition.

For example, a four-season room is the most expensive sunroom addition, costing between $8,000 and $80,000. But the benefit of this room is that you’ll be able to utilize it year-round. An atrium is the least expensive sunroom addition, costing between $10,000 and $35,000.

3. Bathroom Addition

A bathroom renovation can be costly but can yield a significant return on investment.

Adding a bathroom addition will cost between $5,000 and $90,000 with an average cost of $15,000 due to the extra plumbing and insulation required. Adding on a lot of high-end features will push your price tag towards the higher end of the range. It’s a good idea to work with a contractor on a bathroom addition to ensure the project stays on budget.

4. Dormer Addition

A dormer is a roofed structure with a window, allowing for more light on the top floor. 

A dormer is a roofed structure that usually contains a window and is a great way to add curb appeal and natural light to your home. A dormer typically costs between $2,500 and $30,000 with variation due to size. If you’re considering adding a dormer, waiting until you need to replace your roof will help you cut down on the costs.

5. Bump-Out Addition

A bump-out addition, like a breakfast nook, adds a little extra space without costing as much as a full addition.

A bump-out addition lets you expand on the size of a room but isn’t as expensive or complex as a full addition. For example, a kitchen bump-out addition costs between $5,000 and $30,000. Adding a breakfast nook or a walk-in closet are great options for adding a bump-out addition.

6. Second-Story Addition

A full second-story addition costs between $100,000 and $600,000.

Adding a second story to your home is one of the most costly home additions. You can expect to pay between $100,000 to $350,000, depending on whether you do a full or partial addition. 

You’ll likely need to hire a licensed contractor, structural engineer and architect to make sure the addition is completed safely. You’ll also have to pay for demolition, building permits and materials. And you may need to live elsewhere while the project is being completed.

7. Garage Addition

A detached garage can increase your home’s value and add convenience to your daily life.

You might consider building a garage if you don’t already have one located on your property. You can either add an attached or detached garage, and the costs will vary depending on the foundation, electrical system installation, drywall and average square footage.

To build a detached garage, you can expect to pay $40 to $70 per square foot, with the average cost ranging between $19,200 and $28,200. Attached garages will cost about 10% to 15% less than a detached garage since you’re adding on to the existing structure of your home.

House Addition FAQs

Adding a house addition can be a worthwhile project, but you need to do your research first. The following frequently asked questions contain additional information about home additions.

Is it cheaper to add onto a house or move?

Whether it’s cheaper to add a home addition or move depends on a variety of factors, including your current financial situation, the current market conditions and timing. But in general, renovating your current home will likely cost you less money than buying a new house and moving.

How can I finance the cost of adding an addition to my house?

Here are a few ways you can finance your home addition costs:

• Cash-out refinance: A cash-out refinance lets you borrow money against the equity you’ve built up in your home. You’ll refinance your mortgage for a higher amount than you currently owe and take out the difference in cash.
• Construction loans: A construction loan is a short-term loan that lets you finance the costs of your home addition. Construction loans usually come with higher interest rates than mortgages.
• Home improvement loans: A home improvement loan is another way to finance the upgrades to your house. You can take out a home improvement loan as a HELOC or home equity loan¹.

How do I keep home addition costs down?

The best way to keep home addition costs down is by coming up with a budget and a detailed plan. You can also pick out your own materials, find an affordable contractor and do some of the renovations yourself.

When do home additions add value?

A home addition can increase the home value by making the space a more functional and enjoyable place to live. However, not all home renovations will add the same amount of value. Bathroom and kitchen additions tend to come with the highest return on investment.

The Bottom Line

If you love your current home but wish you had more space, you may want to consider a home addition. But a home addition isn’t cheap, so you’ll want to come up with a budget and figure out your financing before getting started. If you’re ready to move forward with your home renovation project, you can apply for a cash-out refinance with Rocket Mortgage®.

¹Home Equity Loan product requires full documentation of income and assets, credit score and max loan-to-value (LTV), combined loan-to-value (CLTV), and home equity combined loan-to-value (HCLTV) ratios. Requirements were updated 2/5/2024 and are tiered as follows: 680 minimum FICO with a max LTV/CLTV/HCLTV of 80%, 700 minimum FICO with a max LTV/CLTV/HCLTV of 85%, and 740 minimum FICO with a max LTV/CLTV/HCLTV of 90%. Your debt-to-income ratio (DTI) must be 50% or below. Valid for loan amounts between $45,000.00 and $500,000.00. Product is a second standalone lien and may not be used for piggyback transactions. Product not available on Schwab products. Guidelines may vary for self-employed individuals. Some mortgages may be considered “higher priced” based on the APOR spread test. Higher priced loans are not allowed on properties located in New York. Additional restrictions apply. This is not a commitment to lend.