Bay Window Cost to Install or Replace [2026 Data]

In 2026, the national average cost to install a bay window is $2,500. Most homeowners spend between $2,000 and $4,000, with costs varying based on window size, frame material, and location. You could pay as little as $1,000 for a smaller bay window with a low-cost aluminum frame, or as much as $8,000 for a larger bay window with a high-end fiberglass frame.

How Much Do Bay Windows Cost by Size?

Bay window size is one of the most significant cost factors, with most homeowners paying $100 to $150 per square foot for materials and labor. A small bay window above a kitchen sink costs considerably less than a larger one in a living room or dining room, where both material quantities and labor demands increase. The style you choose also affects price, since rounded or full bay designs require more frame material and glass than simpler options like a Tudor bay window. Costs vary by size, as the table below shows.

You can use the table below to get an idea of how much your bay window will cost by size, with labor prices increasing significantly for windows larger than 12 square feet:

Window Installer Costs

Labor typically accounts for 40% to 60% of your total bay window installation cost, or $1,000 to $1,500 per window. Expect that figure to climb if your window sits on the second floor or is difficult to reach from the exterior due to landscaping obstacles.

Structural Engineer Costs

If you are enlarging an existing wall opening to fit a new bay window, you will likely need a structural engineer to plan the project, since exterior walls are load-bearing and improper modifications can compromise your home's structural integrity. A structural engineer will cost an average of $550 for this type of work.

General Contractor Costs

Once a structural engineer has drawn up plans, you will need a general contractor to modify your exterior wall before the window installer can proceed. General contractors cost an average of $250 to $500 for work on this type of window.

Additional Pros to Consider Hiring

Enlarging your wall opening to fit a bay window involves cutting out drywall, installing new studs, and cutting a larger hole in your exterior wall. You may need to hire the following professionals for the necessary build-back to restore your home to its finished condition.

• Cost to hire a drywall installer: $150 to $300

• Cost to hire an interior painter: $20 to $50 per hour

• Cost to install window trim: $0.50 to $10 per linear foot

• Cost to hire a siding repair professional: $100 to $500

Bay Window Costs by State: How Does Location Affect Costs?

Where you live affects your bay window cost through two compounding factors: homes in extreme climates require more efficient types of window frames and insulated glass, raising material costs, while installers in high-cost-of-living areas such as California and New York charge more for labor. Costs by state are broken down in the table below.

Bay Window Cost Factors: What Affects the Price?

While size and labor drive the largest share of your bay window budget, several additional factors can meaningfully shift your final installation cost.

Structural Changes

Upgrading to a bay window often means enlarging your existing wall opening, which requires structural changes to maintain proper support. The cost to enlarge a window averages $3,000, though the final total depends on how large your current window is.

Frame Material

Frame material is one of the most consequential choices you will make, affecting not just cost but also durability, curb appeal, and energy efficiency across five primary bay window options. Aluminum sits at the affordable end of the spectrum but offers the least insulation, while fiberglass delivers the strongest energy performance at a higher price point. Costs vary by material, as the table below shows.

Type of Glass

Glass type is another variable that shapes your bay window cost, with double-pane glass serving as the standard choice: it seals insulating gas between two panes and balances affordability with solid energy efficiency. Single-pane glass costs less upfront but provides minimal insulation, while triple-pane glass carries the highest price and delivers superior insulation along with better noise reduction.

You can also consider upgrading to low-emissivity (low-E) glass to boost efficiency or installing window tinting to reduce solar heat gain in hot, sunny areas. Winterizing your window in colder climates can help reduce heating costs, too.

Window Location

Where your bay window sits within your home affects installation cost, with first-floor windows costing less because installers can work without ladders, lifts, or additional safety equipment. For a second-floor bay window, expect labor costs to increase by 5% to 10%.

Number of Windows

Installing a single bay window will cost an average of $2,500, but the price per window could sit lower if you install multiple bay windows at once. Manufacturers and window installation companies will often discount each window if you order more than one at a time.

The table below shows how bay window cost per unit changes based on the number of windows installed:

Hauling Away Your Old Window

Many window installers include old-window disposal in their estimates, but some charge separately for the service. If yours does, budget an additional $150 to $300 depending on the size of your window.

Permits

Some municipalities require a permit for window replacement, and permits cost between $50 and $250 depending on your location. Contact your installer or your local building department directly to get the exact fee schedule for your area.

Why You Should Hire a Bay Window Pro

Bay window installations are highly technical, and improper installation can lead to structural failure and severe safety concerns. Unless you have construction experience, you should not attempt to build a bay window yourself. Window companies typically charge between $100 and $150 per square foot, with additional cost for structural work in new bay window installation.

Here’s why it’s ideal to hire a bay window pro

There are many reasons why you’d be better off hiring a contractor to install or replace bay windows:

• Bay window installation is challenging: Installing new bay windows involves complicated structural work. Replacements, while somewhat easier, are still labor-intensive.

• Safety concerns: Bay window installation poses safety risks due to working above ground and handling heavy materials. 

• Protected by insurance: Pros carry insurance that will protect you and your property in the event of any issues during the installation.

• Better rates for materials: Many pros get better rates for tools and materials than individual homeowners.

• Faster turnaround: A professional company is almost always more efficient. You will get your windows installed faster and better.

Bay Window Repair vs. Replacement: Which Costs More?

Replacing a bay window costs an average of $2,500 while repairing a window costs an average of $400. Even major bay window repairs like replacing window glass cost less than a full window replacement, averaging $1,700. In most cases, it's more cost-effective to repair your bay window.

However, if you've had ongoing or recurring problems with your bay window or you know it's reaching the end of its lifespan, you should replace the window rather than repair it . A replacement will cost more up front, but you could spend less over time, and you'll see a higher bump in property value.

How to Save Money on Bay Window Installation

Bay window costs can reach up to $8,000, making them some of the most expensive windows to install. You can use the tips below to keep your installation cost as low as possible.

• Keep your window size the same: If you’re replacing an old bay window with a new one, keeping the size the same can save you an average of $3,000.

• Consider more affordable materials: You can keep up-front costs down by choosing more affordable frame and glass options, like aluminum or vinyl frames and single-pane or double-pane glass. Just make sure to consider your local climate and long-term costs, as more affordable materials tend to be less insulating and don’t last as long. Choose double-pane glass and vinyl frames to balance cost, longevity, and efficiency.

• DIY what you can: Installing a bay window is a job best left to professionals, but if your project involves buildback after the installation, you can save a few hundred dollars by patching drywall, painting, and installing window trim yourself. You can also save on window cleaning costs and ongoing window maintenance by doing the work yourself.

• Haul away your old window yourself: You can save $150 to $300 if you can haul your old window to the dump yourself.

Do Bay Windows Increase Home Value?

Yes, one of the benefits of bay windows is that they drastically improve curb appeal and positively impact home value. Replacing windows provides a return on investment (ROI) of between 80% and 90%, but installing a new bay window can drive ROI even higher, sometimes up to 95% or 100%. This is something to consider when using a window buying guide to determine if a bay window is right for you.

How Angi Gets Its Cost Data

Home is the most important place on earth, which is why Angi has helped more than 150 million homeowners transform their houses into homes they adore. To help homeowners with their next project, Angi provides readers with the most accurate cost data and upholds strict editorial standards. We extensively research project costs to develop the pricing data you see, so you can make the best decisions for you and your home. We rely on 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. 

Want to help us improve our cost data? Send us a recent project quote to [email protected]. Quotes and personal information will not be shared publicly.