How Much Does a Home Addition Cost in 2025?
Explore the essentials of house framing, including material choices, construction methods, and key considerations to ensure a sturdy and lasting structure for your home.
Plumbing, electrical, and other components add to the complexity and cost of home additions.
Adding a second story to an existing building costs more than building outward.
Professionals to hire for this project may include architects, construction managers, general contractors, and structural engineers.
Home additions can increase home value with an average ROI of 20% to 50%.
This article was updated using automation technology and thoroughly reviewed for accuracy by HomeAdvisor Editor Ryan Noonan.
A home addition is a fantastic way to create more living space and boost your home's value—whether you're dreaming of a larger kitchen, an extra bedroom, or a sun-filled sunroom. The average home addition cost is around $51,047, with most homeowners spending between $21,933 and $83,333. Costs can range from $80 to $200 per square foot, depending on factors like location, size, and the quality of materials. Let's dive into the various factors that influence the cost of a home addition to help you plan your budget for this exciting project.
Home Addition Cost Factors
When you meet with home addition builders in your area to discuss your project, review the various factors determining the cost of a home addition. The three main factors are size, materials, and type of home addition.
Size
The bigger your addition, the more it will cost. Home additions typically run between $80 and $210 per square foot, including labor and materials. Thinking about adding a second story? You can expect costs between $100 and $300 per square foot. Overall, second-story additions usually range from $100,000 to $250,000, but extensive projects can reach $600,000 or more.
| Square Footage | Average Price Range |
|---|---|
| 100 | $8,000–$21,000 |
| 200 | $16,000–$42,000 |
| 300 | $24,000–$63,000 |
| 400 | $32,000–$84,000 |
| 500 | $40,000–$105,000 |
| 1,000 | $80,000–$210,000 |
Additionally, note that second-story (upward) additions typically cost between $100 and $300 per square foot.
Materials
As you might expect, the materials you choose for your home addition play a big role in the total cost. Doors, roofing, windows, insulation, and paint can add up quickly. Opting for different types of materials can influence the price and add complexity to your project. Don't forget about essentials like electrical and plumbing parts or HVAC components—they're important cost factors to consider.
| Material | Average Cost |
|---|---|
| Foundation | $5–$37 per sq. ft. |
| Framing Lumber | $5 per standard 4 x 4 |
| Insulation | $0.20–$2 per sq. ft. |
| Window | $250–$1,000 each |
| Exterior Door | $500–$2,000 each |
| Interior Door | $250–$1,150 each |
| Drywall | $1.50 per sq. ft. |
| Electrical Work | $50–$100 per hour |
| Plumbing | $600–$1,600 total |
| Roofing | $120–$400 per roofing square (100 sq. ft.) |
| Siding and Trim | $1–$30 per sq. ft. |
| Flooring | $2–$22 per sq. ft. |
| Paint | $100–$530 total |
Type
The type of home addition you're considering also affects your project cost. Whether you want a cozy sunroom, an extra bedroom, or a spacious garage, each style has its own price tag.
Balcony addition costs age, which is generally less than building porches and decks.
A bump-out addition typically costs between $4,000 and $30,000.
A cantilever costs around $15,000 to $25,000 on average, adding square footage to the upper floor of a home with support beams.
Dormer addition costs adds a roofed structure with a window to increase the usable space in a loft or attic.
The cost to add a garage ranges from $25,000 to $50,000, depending on whether you want to include HVAC and electricity.
In-law suite additions can vary significantly. A simple in-law bedroom unit typically costs between $8,600 and $21,600, while a full, unattached in-law suite can cost up to $100,000 or more.
Adding a modular or prefabricated room runs you $20,000 to $30,000.
Adding a front porch to your home costs between $4,600 and $22,200 on average.
A second story addition costs as much as $500 per square foot, making it one of the most expensive home addition types.
Additional Cost Factors
As you estimate your home addition costs, consider these other factors that can greatly increase your overall price.
Excavation and Prep
Before you can start building, you might need to take care of demolition and site prep. Excavation typically costs around $1,500 to $5,800, but for larger projects—like adding a second floor or installing a basement—it could run up to $10,000.
Permits
Since a home addition can significantly change your house's structure, you'll likely need to apply for the right permits. Permit costs depend on where you live and what your project involves, ranging from $200 to $3,000.
Cleanup Costs
Don't forget about the cleanup! After the construction dust settles, you'll want your new space to shine. On average, construction cleanup costs around $470. While many general contractors handle the initial cleanup, you might consider hiring a professional cleaning service for a thorough, final touch.
Insurance
Insurance is another important piece of the puzzle. Your current homeowner's insurance might not cover your new addition, especially if it significantly increases your home's value. You may also need to add 'dwelling under construction' coverage during the build. Be sure to talk with your insurance provider to see what adjustments are needed.
Home Addition Cost by Room
Different rooms have different needs and unique characteristics, so the type of room you add to your home also impacts the total cost of your home addition project.
| Room | Average Cost |
|---|---|
| Attic | $40,000 |
| Bathroom | $35,000 |
| Bedroom | $62,500 |
| Dining room | $35,000 |
| Kitchen | $55,000 |
| Laundry room | $8,070 |
| Living room | $30,000 |
| Mudroom and sunroom | $12,000 |
Home Addition Labor Costs
Bringing your home addition to life takes a team of skilled professionals. Depending on your project, you might need designers, demolition contractors, and other specialists. Keep in mind that labor can account for up to 50% of your total budget.
Architects
A great home addition starts with a solid plan. A local architect can help ensure that your home addition seamlessly matches the rest of your house. The average cost to hire an architect typically makes up 5% to 20% of your total project budget.
This is more than the cost to hire a draftsperson because the architect is much more involved in the actual design of the home addition. In contrast, the draftsperson may be responsible for drawing the detailed plans that the architect creates.
Construction Managers
Construction managers oversee the entire project, hiring subcontractors and managing everything needed to get the job done. They may also apply for the relevant building permits on your behalf and collaborate with the architect for clarification and guidance. Average construction manager fees take up 5% to 15% of the project total.
General Contractors
After the architect has drawn up the designs and everyone is in agreement, general contractors perform the general labor needed to make your home addition a reality. This may include laying the foundation, framing, roofing, drywall, and paint. For home additions, general contractor rates range from 10% to 20% of the project cost, also called “cost plus.”
Electricians
Many home additions involve some level of electrical work. The project's specifics vary considerably, so ask local electricians for quotes specific to your home addition. Expect to pay $50 to $130 per hour for standard work.
Plumbers
While you may not need to find a local plumber when adding an extra bedroom, plumbing is crucial for kitchens and bathrooms. Pro plumbers can ensure sinks, showers, bathtubs, and other similar fixtures are installed properly. Plumbers charge anywhere from $45 to $150 per hour with a minimum service fee.
Structural Engineers
Whether your home addition builds up or builds out can affect your home's structural integrity and foundation. To ensure everything is up to code, consult a structural engineer in your area to review the home addition plans and inspect the construction once it’s completed. The cost to hire a structural engineer ranges from $70 to $250 per hour.
Does an Addition Increase Home Value?
Good news—home additions generally boost your home's value! When you decide to sell, you can recoup some of your construction costs. The return on investment (ROI) depends on the type of addition. For example, adding a primary suite or bathroom offers an average ROI of 22% to 30%, while adding an outdoor deck can bring an ROI of 40% to 50%.
Budgeting for a Home Addition
Looking to save money on your home addition without sacrificing quality? Here are some tips to help you get the most bang for your buck:
Keep it simple: Opt for straightforward designs that focus on functionality.
Go standard: Choose standard-sized windows and doors to avoid the extra cost of custom sizes.
Reuse materials: Whenever possible, repurpose existing materials.
Think long-term: Invest in energy-efficient materials to save on future utility bills.
Do it right the first time: Ensure plumbing, electrical, and HVAC work is done properly to avoid costly fixes down the road.
Build out, not up: It's usually cheaper to expand outward than to add another story.
Shop around: Get multiple quotes from local contractors to find the best deal.
How HomeAdvisor Gets Its Cost Data
No place is more important than your home, which is why HomeAdvisor connects homeowners with local pros to transform their houses into homes they love. To help homeowners prepare for their next project, HomeAdvisor provides readers with accurate cost data and follows strict editorial guidelines. We surveyed thousands of real customers about their project costs to develop the pricing data you see, so you can make the best decisions for you and your home. We pair this data with research from reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects.
Frequently Asked Questions
Several elements affect the overall cost of a home addition, including the type of room being added (e.g., bedroom, bathroom, kitchen), the size of the addition, the materials chosen, labor expenses, and regional pricing variations. Additional considerations like permits, demolition, foundation work, and utility installations (plumbing, electrical, HVAC) also play significant roles in determining the final cost.
Yes, obtaining a building permit is typically required for home additions. Permit requirements and costs vary by location and the scope of the project. It's essential to check with your local building authority to understand the specific regulations and fees applicable to your area.
It's generally less expensive to build out than to build up. Expanding your home's existing footprint usually requires less structural reinforcement and planning complexity. Building out lowers material and labor costs while preserving your home's existing structure.
The timeline for completing a home addition can vary based on the project's complexity, size, and unforeseen challenges. On average, the process can take several months and encompass design, permitting, construction, and finishing phases. Factors like weather conditions, material availability, and contractor schedules can also impact the duration.
Adding space to your home can enhance its market value, especially when the addition improves functionality or adds desirable features like extra bedrooms or bathrooms. However, the ROI can vary based on the quality of the work, the type of addition, and the real estate market in your area.
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