Key takeaways

  • Home additions are time intensive and pricey, easily hitting six figures.
  • Zoning and local regulations will impact the scope of your project.
  • Quotes from multiple contractors are a must to determine the full cost.
  • Home equity loans and lines of credit are the most common way to finance a home addition.

You’re feeling pinched in your house; you need more space. Or, you love your house — but you still need more space. A home addition could be the solution. It’s a thought many homeowners have had over the last two pandemic years, and given the shortage of housing and skyrocketing property prices, adding rooms to residences has gotten more common than ever — even though they are some of the most expensive and time-consuming of home renovations.

The cost of a home addition typically ranges from $18,000 to $81,000, according to HomeAdvisor. But really, you can expect to spend anywhere from $5,000 to $150,000 depending on the type and size of the addition, the materials used, labor and your location, according to HomeAdvisor. Here’s how the prices play out, what contributes to the costs, and some tips on financing and saving money on the project.

How much do home additions cost?

Since a home addition can encompass a tremendous variety of things — anything from a single small room to an entire story or wing — generalizing about cost is tough.

The size of the addition and the nature of the addition are the two key factors. Building materials, current layout and zoning requirements will also influence costs. Because of these variations, homeowners with two similar properties undergoing the same additions can end up with significantly different tabs.

Online calculators can offer a rough idea of what you’re in for, but you will need a professional builder’s estimate to get a true idea of cost. Also keep in mind that unforeseen expenses may pop up, and for this reason, it is a good idea to budget about 20 percent extra for the home addition.

What affects the cost of home additions?

The size of your home, its current layout and your local zoning regulations — among other factors — will all play a role in the total cost of an addition.

The size and extent of the house addition

Home additions are typically priced per square foot. However, while size does matter, calculating the price by square foot alone will likely result in an inaccurate estimate. A 100-square-foot addition will not cost double what a 50-square-foot addition costs, but just increase the price by one-third, according to HomeLight.

No matter what the size of the renovation is, a home addition often involves the same amount of work for the contractors, from initial design to final clean up. The complexity of the project is a much more significant factor when determining how much you will pay.

Basic additions — that is, closets or bare-bones rooms with rudimentary electrical wiring — generally cost the least because they are easier and quicker to complete. Once plumbing gets involved, the cost begins to climb. And it continues to do so with each additional detail, like windows, doors and walls.

The house addition’s location

Indoor and outdoor obstacles need to be removed or relocated to make room for an addition, which in turn drives up the project cost. Where do you plan to build your home addition, and what’s there right now? Think about landscaping, HVAC systems, electrical wiring and even hidden features like underground pipes.

Some zoning laws may also prevent you from building to the edge of your property. This could limit the size and scope of the addition.

The house addition’s building materials

Most people who build home additions want the new parts of their homes to match the existing residence. If this is you, you will have to pay for whatever materials were originally used to build your house — and if that means wood siding, triple the cost of vinyl siding, c’est la vie. You will also likely need to extend the roof to cover the addition, and this too should ideally match the original.

Material Average price
Paint $15-$40 per gallon
Drywall $20-$30 per linear foot
Concrete $4-$8 per square foot
Steel beams $100-$400 per foot
Framing $4-$16 per square foot
Insulation $0.40-$2 per square foot

Contractor costs for the house addition

From architects and engineers to painters and roofers, quite a few trades are involved in home additions.

The more skilled or specialized the subcontractor, the more expensive their services will be. All told, contractor labor costs make up about 30 to 50 percent of a total budget, according to Angi. Make sure to get quotes from at least five different general contractors before you make up your mind.

Local zoning laws

Every municipality has different zoning laws for home additions, and your home addition cost could go up if you need to obtain permits and meet certain compliance standards. Water drainage, septic systems and electrical wiring are just a few examples of components that could be regulated. A qualified local builder will be able to inform you about the requirements in your area.

Home addition costs by room type

Another way to calculate costs of a home addition is by the type of room.

  • Home office: The cost of adding a spare room or home office is between $18,000 and $35,000. If you want it to serve as a spare bedroom as well it will need to be at least 70 square feet, have a window and a closet.
  • Master bedroom: A master bedroom costs between $25,000 to $100,000. The more luxurious the project, the more it will cost, but it may be worth it if the ROI is good.
  • Bathroom: Building out a bathroom can cost between $20,000 to $60,000. Although it is one of the most expensive rooms to add or remodel, according to the National Association of Realtors, it also increases the resale value of the house by more than 50 percent.
  • Kitchen: The cost of adding a kitchen depends on the size, fixtures and appliances. On average, it will cost around $65,000. Luxury kitchens with high-end appliances can cost as much as $125,000 or more.
  • Second story: Adding a second floor to a home is almost like building an entire house from scratch. The cost can run $100 to $500 per square foot, especially since replacement of the roof is going to be involved. Depending on how many rooms are being built, the total expense can easily slide into six figures.

Tips for saving on home addition costs

If you’re worried about how much house additions cost, there are plenty of tricks you can use to bring the final price of a new room down.

  • Convert or extend an existing space. A pop out requires much less labor than an entirely new room.
  • Take advantage of tax refunds and rebates. There are many federal, state and local ways to write off taxes on energy-efficient construction and appliances.
  • Use less-expensive materials. Many synthetics or prefabricated materials are convincing substitutions for “the real thing” — at a fraction of the cost.
  • Identify DIY projects. You may be able to save money by doing jobs or adding finishing touches on your own.

How to finance the cost of your home addition

Given how expensive home additions are, you might need to borrow to pay for the project. Even if you have the means to cover your home addition, getting financing is a good way to keep your savings intact.

Home improvement loan

Home improvement loans, which are a type of personal loan, work like any standard loan. You borrow a lump sum then make monthly payments for the duration of the loan term.

Home equity loan

A home equity loan is a second mortgage, where you borrow money using your house as a collateral. Home equity loans have fixed interest rates and a set repayment period, similar to a home improvement loan. If you itemize your taxes, the interest you pay may also be tax-deductible.

Home equity line of credit

Although a similar concept as a home equity loan, a home equity line of credit (HELOC) acts like a credit card, where you can borrow against it, repay the loan and then borrow again up to a certain limit. They have variable interest rates and a set time frame for borrowing money, usually up to 10 years.

Unlike home improvement loans and home equity loans, HELOCs are much more flexible to help you cover varying costs during your addition.

Next steps in your home addition

If you love the location of your house but wish you had more space — or different sorts of space — a home addition may be a great option. Before you commit to one, determine the scope of your project. Think about what type of addition would be best for your lifestyle needs.

Then find the right contractor and source of funding for your situation. Shop around for the best home improvement loans.

Home additions don’t come cheap — the most elaborate, multi-room projects can easily exceed $100,000. Still, they’re a lot less expensive and less hassle than buying and moving to another place. And when done right, a home addition can make a house feel brand new.