How Much Does a Bump-Out Addition Cost in 2025?
A bump-out addition costs an average of $27,000
A bump-out addition costs $27,000 on average, or ranges from $1,800 to $65,000 at the lowest and highest ends.
Your bump-out addition cost depends on room size, finishes, room type, and any plumbing or electrical upgrades you choose.
A bump-out addition costs $90 to $300 per square foot.
A bump-out addition increases total square footage, which can increase property value.
Proper budgeting eliminates surprise costs and hiring a professional addition contractor ensures a structurally sound, code-compliant build.
This article was updated using automation technology and thoroughly reviewed for accuracy by HomeAdvisor Editor Ryan Noonan.
You’ll spend an average $27,000 bump-out addition costs, with most projects costing between $10,000 and $43,000. Costs can range from as low as $1,800 to as high as $65,000. Room size, finishes, and the pros you hire will move that number up or down.
Because these micro-additions are smaller and often don’t need full foundations, they’re far less expensive than a full-size addition. Set a realistic budget upfront and work with a qualified bump-out addition contractor to ensure every dollar delivers usable square footage and long-term value.
Bump-Out Addition Cost Factors
Size, room type, finishes, and labor make up most of your bump-out bill. Here’s a closer look at the main bump-out addition cost factors.
Room Size
Size drives the bulk of your cost because pros often price these projects by the square foot. On average, expect to pay between $90 and $300 per square foot on a bump-out addition.
| Room Dimensions (Feet) | Square Footage | Average Cost Range |
|---|---|---|
| 2x10 | 20 | $1,800–$6,000 |
| 2x15 | 30 | $2,700–$9,000 |
| 4x10 | 40 | $3,600–$12,000 |
While adding just a couple of feet to the width of a room may not seem like much, it can significantly increase the square footage of your space. A two-foot bump-out that runs the length of your 15-foot kitchen adds 30 square feet, which is a 20% size increase. This would provide you with ample room to install a breakfast nook or add a spacious kitchen island, as well as space for an additional appliance. A three-foot bump out in a 30-foot living room gives you 90 square feet of extra space, which is plenty for a small home office, book nook, or craft area.
Finishes
After the shell goes up, flooring, paint, trim, and fixtures turn it into a livable space—and each line item adds to the final tab.
Flooring
Installing new flooring costs $3 to $22 per square foot. However, there are plenty of flooring options, and you'll want the flooring to match the existing space. For bump-outs that are their own space, like a home office, laundry room, or craft space, you have more flexibility with flooring choices.
Laminate flooring is a good choice for those on a tight budget. For warmth, carpet or hardwood is a better option. In moisture-prone spaces like bathrooms or kitchens, tile is a reliable option.
Walls and Trim
Don’t forget the walls: painting costs an average of $2 to $6 per square foot when you hire a professional.
Windows
Installing windows costs $575 to $1,500 per window, depending on the size and number of windows.
Electrical
While not always necessary, hiring an electrician costs $50 to $100 per hour. You must hire an electrician if the bump-out requires additional lighting, outlets, or a ceiling fan.
Room Type
Depending on which room you bump out and what you plan to do with the extra space, you'll need to budget for the materials and installation required to outfit the space appropriately.
| Room Type | Average Cost per Sq. Ft. |
|---|---|
| Kitchen | $100–$300 |
| Bedroom | $90–$200 |
| Garage | $90–$120 |
| Bathroom | $200–$300 |
Labor
Plan for multiple pros on site and budget accordingly for labor.
| Professional | Average Cost per Hour |
|---|---|
| General contractor | $50–$150 |
| Plumber | $45–$200 |
| Electrician | $45–$200 |
Permits
Even for a small addition, you’ll need to acquire a building permit before construction can begin. Building permit costs vary depending on the size of your addition and local regulations, but you can expect to pay between $460 and $2,900.
Does a Bump-Out Addition Increase Home Value?
Adding square footage almost always boosts resale value. Versatile micro-additions—such as breakfast nooks or pocket home offices—allow future buyers to adapt the space to their needs, further enhancing its appeal.
Budgeting for a Bump-Out Addition
Building a bump-out addition requires professional expertise and labor, but there are several steps you can take to help your project stay on budget:
Share your budget early. Inform your contractor about what is non-negotiable and where you can be flexible, so they can source finishes that align with your budget.
Search for energy-efficiency rebates. Double- or triple-pane windows may qualify for local incentives and cut future energy bills.
DIY light finishes. Painting and trim work are weekend-friendly projects that can shave labor costs.
Collect at least three bids. Multiple quotes help you identify outliers and arrive at fair pricing.
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. After a project is complete, we survey real customers about the 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
How far you can push a room depends on the structure you choose. A cantilevered bump-out can extend 24 inches before building codes require its own footing or foundation. Anything longer needs engineered support and a permit. Check local codes or consult with a structural professional before finalizing plans to ensure your design remains safe and compliant.
Most bump-outs are completed within one to four weeks, even with minimal electrical, plumbing, or HVAC work. Their compact size means less demolition, simpler inspections, and fewer weather-related delays compared to a full-scale addition. Your contractor can provide a more precise timeline once they have determined the scope, materials, and permit schedule, but plan on having the extra square footage ready in approximately a month.
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