roof construction

Home Additions: What You Need To Know

February 28, 2024 11-minute read

Author: Patrick Chism


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When it comes to putting an addition onto your house, it can be tough to know what you don’t know. How will an addition affect resale value? What building codes are involved? Can you DIY it or do you need to hire a contractor?

Whether you're thinking of adding on a second floor or just putting in a dormer window, you should consider all of these questions before adding on to your living space. In this article, we’ll give you starter information that will be useful if you're thinking about making a home addition in the near future.

Should You Add An Addition To Your House?

Whether it's a small bump-out addition with a remodel, or a full-blown addition project, house additions are investments for homeowners. If you do not plan on moving anytime soon, you have more incentive to make it yours. The value you receive from a home improvement project can be enjoyed for many years to come.

However, if you sell your house in the future, you need to think about the resale value. Make sure the add-on is cost-effective. If the value of your home increases with a tasteful addition, investing in your home could have a high return on investment.

Questions To Ask Yourself

A home addition can require a big investment of your time and money. It can also disrupt the comfort of your home for a long time. It’s important to ponder the following “how much” questions before you set out on a home addition endeavor:

  • How much do you want to spend in total?
  • How much room do you want?
  • How much do you need this space?
  • How much are you willing to put up with the dust, noise and strangers working on your house?
  • How much time will it take?


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How Much Does A Home Addition Cost?

How much money an addition costs depends on the variables of your home and what you want. The bigger the project, the more money it will cost.

The national average cost for a home addition is $50,114, while the typical price range is anywhere between $22,216 – $81,613, according to HomeAdvisor. However, the cost to add an addition to your home can surpass $100,000 depending on the following factors:

  • Room type
  • Style
  • Addition size
  • Materials used

Another impact to your overall cost is whether you hire a contractor or choose to do it yourself (DIY). If you're hiring a contractor, you may see a wide range among different contractor estimates. You may be able to DIY the project, but you must be confident in your skill and willing to sacrifice your time. If you end up needing some financial help, there are some strategies you can use, including a cash-out refinance, construction loans, home improvement loans and more.

To give you a better idea of what to expect, let’s take a look at the costs of home additions broken down in terms of materials and labor, according to HomeAdvisor.

Home Addition Material Costs

Below are some of the most commonly used home addition materials and their average costs.

Home Addition Material

Average Cost

Exterior doors

$500 – $2,000 each

Interior doors

$250 – $1,150 each


$1 – $3 per square foot


$0.50 – $15 per square foot


$4 – $25 per square foot


$2 per square foot


$2 – $5 per square foot


$75 – $600 per square foot

Siding and trim

$1 – $30 per square foot

Support beams

$1,150 – $4,600


$250 – $1,000 each

Home Addition Labor Costs

In this table, you’ll see home addition costs broken down by the labor of a variety of professionals.

Home Addition Professional

Average Price Range


$75 – $100 per hour

Demolition technician

$500 – $10,000


$40 – $100 per hour

HVAC technician

$50 – $100 per hour


$50 – $200 per hour


$40 – $80 per hour

When it comes to making home additions, homeowners need to set some limits for themselves. It’s easy to say you want to double the square footage of your home, but is that something you can afford? It’s crucial to develop a realistic, thought-out budget before you begin your home addition project.

Get approved to refinance.

See expert-recommended refinance options and customize them to fit your budget.

Is This A DIY Project Or Will You Hire A Contractor?

After considering the costs of home addition materials and labor, it’s time to decide between two options that will also impact the total cost of the project – doing the project yourself or hiring a professional. Let’s take a look at some of the expectations of both.

Do-It-Yourself (DIY)

With DIY, you’ll have to make sure you have the skill and know-how to do the home addition right. Same for anyone working with you. You don't want to get started on a project to then figure out you're in over your head.

Before you begin, make sure you know your limitations and when you need help. If you can frame and hang drywall, but the thought of wiring makes your skin crawl, why not hire out a contractor? If you have a friend with electrical experience, maybe you could get them to help you out for some free pizza or at a discount.

Hire A Contractor

It’s no small project to add an addition onto your home, so you should ensure that whoever is completing the work is knowledgeable and experienced. If you aren’t very confident in your own abilities, it’s likely a good idea to hire a professional contractor.

General contractors can help alleviate a lot of the stress that comes with any type of renovation project. Some of the things they can help with include:

  • Planning and designing a room addition that fits your budget
  • Navigating the permit and inspection process
  • Hiring and overseeing the work of subcontractors
  • Preparing the site
  • Ordering and arranging delivery of building materials, fixtures and finishes

The right contractor can build your dream addition, and their work may up your home's resale value.

How Do You Find A Reputable Contractor?

Let’s take a look at some ways to find a reputable contractor.

  • Get a referral from a friend. If you don’t know anyone well-versed in the industry, ask your family, friends and co-workers who’ve had similar work done. If they’re thrilled with the work they had done, they’ll be happy to tell you all about it. On the other hand, if they had an awful experience, they’ll be happy to tell you all about that as well.
  • Pay for a contractor grading service. One popular option is a contractor grading service like, whose model includes paying a subscription fee for their grading.
  • Use a free contractor grading service. If you’re not fond of the idea of paying a fee to have someone rate a company, there are several other options., and all follow the Angi model, except they offer it for free. All services offer grades based on user reviews and support themselves based on advertising bought on their sites, some of which can be contractors paying for a call-out in the listings.

Whichever avenue you choose, make sure you talk to several contractors for their ideas and estimates before any work begins. Also make sure they’re insured, licensed and bonded to avoid any liability, tax or quality issues.

Home Addition Ideas

Interested in adding square feet to your home, but not sure where to start? Or maybe you know the addition you want to make but aren’t sure what it entails.

Let’s go over some of the most popular home addition ideas and their typical costs.

Kitchen Addition

Man installing kitchen cabinets during kitchen renovation.

The kitchen can make or break a home. Many homes have a kitchen that’s too small or one that’s poorly designed. If you like to cook and entertain, having a big, well-thought-out kitchen is a dream.

Gather ideas of what you would like your kitchen addition to look like. You can search kitchen blueprints online and try to mock up one of your own. If it’s in the budget, you can hire an architect to put your dreams on paper.

When considering a kitchen addition, determine whether you want to replace your appliances and cabinetry. These are two costly factors, but if you forgo them with your new addition, your kitchen may not flow and may feel segmented or incomplete.

Cost Information

Kitchen additions are one of the most expensive home additions because they require electrical work, plumbing and appliances. You can expect to spend anywhere from $20,000 to $90,000 on a kitchen addition.

Mudroom Addition

Mudroom addition with backpack hooks with benches and under bench storage.

A mudroom can add many benefits to your home. They’re a great place to store shoes, coats and backpacks. They function well as an informal entry to the home. They’re easy to clean, making it a good place to bring in dogs with dirty paws or kids with dirty boots.

Mudrooms benefit from benches with drawers, built-in shelving and lockers or cubbies. Depending on how you’re using the room, you may want a utility sink to make cleanup quick.

Cost Information

Mudroom additions range in cost based on size and materials used. For a small 6x6 room, costs are going to average around $4,000. A large room can cost as much as $12,000. Keep in mind this is just for the room. Any benches and storage will cost extra.

Sunroom Addition

Sunroom addition with large windows.

A beautiful sunroom can elevate even the most modest home. Whether you’re thinking of enclosing an existing porch or building off your front entryway, a sunroom brings a lot of natural light into the home.

Sunrooms come in a few varieties, including:

  • Three-season sunrooms: These sunrooms aren’t well-insulated and cannot be used in the coldest months of the year.
  • Four-season sunrooms: These sunrooms are well-insulated and are functional rooms throughout the winter. They’re more expensive than three-season varieties, but you’ll get more use out of them.
  • Solariums: This is a type of sunroom made entirely of glass. Because of the thermal technology to keep the room insulated, solariums tend to be more expensive than a four-season room. However, they can double as greenhouses for flowers that require full sunlight.

Cost Information

You can expect to spend $8,000 – $11,000 for a simple sunroom or upward of $80,000 for a 200 square foot space with electrical wiring and heating.

Bathroom Addition

In progress bathroom addition.

A major way to increase the value of your home is by adding on a bathroom. You could convert a closet or the area under the stairs into a water closet, or you could dive in and add a whole room entirely. Obviously, the more you add on, the more it will cost.

Before you go planning your new bathroom, you need to look at your piping. Do you have existing water and waste piping near where you want to put the addition? If you’re putting the bathroom in an unfinished basement, the piping is right there.

But if you’re looking at putting a bathroom in an addition on the back of the house, you’ll probably have to pay more to run a pipe. Costs like these can accumulate quickly, especially when you start adding the cost of fixtures.

The good news is that, even if a bathroom addition is costly, if done right, it can greatly increase your home value. Just think how much more appealing a two-bathroom home is than a single bathroom home. If you’ve got growing kids or frequent houseguests, you understand the reason another bathroom is valuable.

Cost Information

The cost of a bathroom addition can vary greatly depending on how luxurious you go with it. Adding a smaller, modest bathroom will cost you around $35,000 while adding a fancier, larger bathroom of 100 square feet will cost around $90,000.

Home Office Addition

Woman stretching at home office desk.

With more people working from home, the value of a functional home office is increasing. Yes, you could convert a spare bedroom or a section of the basement, but if you don’t have either of those to work with, adding on an office is something to think about.

If you need a space with limited distractions where you can work, you need a home office. For small business owners working out their home, a home office may be a cheaper alternative than renting or buying a commercial property.

Cost Information

The cost to add a home office to your house will increase depending on the size of the room and the cost of any fixtures, but you can expect to pay around $15,000. If the office you build could also be a bedroom, you could list it as such if you sell your house. This will increase your resale value.

Smaller Additions

There are a couple smaller additions you can make to increase the charm and value of your home. These small additions cost much less than adding on a whole new room. They can also open your space, making it feel larger than it is.

Dormer Addition

Dormers with siding addition.

Adding a dormer onto your second floor is a great way to bring in light and expand your usable space. A dormer is a roofed structure that usually includes a window, and it’s typically added to increase usable space in a loft or attic.

Costs vary depending on your type of house, total square footage and the pitch of the roof. For dormers, hire a contractor experienced with roofing.

Bump-Out Addition

Side of house with small amount of side yard and fence.

Bump-out additions allow you to add on a small space without having to pay for new foundation work. These additions extend out over the edge of the house and can add extra space onto a current room.

Depending on what room is attached, the space of the bump-out could be used differently. In kitchens, popular bump-out choices are to add a bench and window for a dining room or to add a pantry. If you’re adding a bump-out to a bedroom, it could be used as a walk-in closet. With a living room, a bump-out can be used for a built-in entertainment center.

Bigger Additions

If you’re looking to really expand your home, you could put in a huge addition. These additions will cost a lot more and could be riskier if not done right. But if they work, they will add significant value to your home.

Second-Story Addition

Attic in midst of a remodel.

Adding a second story onto your current home is a huge step. If it works, it could nearly double your home’s square footage, turning your one-story into a two-story home. You could add on a bathroom and an extra bedroom in the new space or build out your dream master bedroom.

A second-floor addition is expensive, costing $300 – $500 per square foot. A second-floor addition is the perfect way to build up, not out. This could help if your property lines are tight.

Since a second-story addition is a complex process with a high margin for error, make sure you hire an experienced contractor. Check their references on similar projects, fully vetting them before hiring them.

Garage Addition

Interior of finished garage.

If your current home is garage-less or is in desperate need of more storage and workspace, adding a garage onto your home can greatly increase its value. You must consider where your current driveway is and how the addition will sit.

A freestanding garage is more expensive than an attached one, but can present fewer construction challenges. A freestanding garage keeps dust and smells away from the home, but convenience of an attached garage makes going to the garage from the home easy. This transition is even more of a plus with bad weather.

As with other additions, make sure the garage addition blends in with the architecture of the current home.

In-Law Suite

Spacious kitchen and living area of basement in-law apartment.

Another larger home addition you can consider – especially if you have frequent visitors or family members who need additional support and care – is an in-law suite. An in-law suite is a small studio or apartment that adds separate living quarters to your property.

In-law suite additions are on the pricier side, costing anywhere from $50,000 – $100,000.

The Bottom Line

Before you begin the exciting adventure of a home addition, make sure you secure the proper financing for what you’ll need to complete the project. This is especially important since the addition will likely increase the overall value of your home.

Ready to start your home additions? Apply for a cash-out refinance today. You can also give us a call at (833) 326-6018.

Get approved to refinance.

See expert-recommended refinance options and customize them to fit your budget.

Patrick Chism

Born and raised on a farm in the Ozarks, Patrick has a knack for making the best out of the worst situations. Where others see flooded farmland, he sees lakefront real estate. Where others see an infestation of bees, he sees free pollination and a upstart honey shop. Patrick’s articles will help you make the most out of the least, maximizing your returns while keeping a close eye on the wallet. When he’s not writing for Rocket Mortgage, Patrick likes hiking, gardening, reading and making healthy foods taste like unhealthy foods.