How Much Does Window Sill Replacement Cost? [2025 Data]

Window sill replacement costs an average of $400, and most homeowners pay between $150 and $700 to have a window specialist carry out the work. You could pay as little as $100 to replace an aluminum or vinyl sill on a small hopper window or as much as $1,100 to replace a wooden sill on a larger bay window.

Cost by Window Sill Material

Much like the cost of window replacement, the cost to replace a window sill depends on the material you need to replace. Most modern windows have vinyl or wood sills with window capping over them, but you have other options. Aluminum and vinyl are the most affordable materials, fiberglass, stone, and tile are the most expensive, and composite and wood window sills fall somewhere in the middle.

The table below includes costs for different window sill options for the materials alone. Labor costs can also vary by material, especially in the case of a tile window sill that requires additional time and effort to install. Keep in mind that you’ll get the best curb appeal if you choose a sill material that matches or complements your window frame material.

Size of Window Sill

Most window repair specialists will charge per linear foot, which means the size of your window sill plays an important role in your total replacement cost. The average cost to replace a window sill per linear foot is $75 to $100, including materials and labor. Prices can range from $55 up to $150 or more, depending on the complexity of the job.

Window Repair Specialist Costs

Labor will account for between 80% and 90% of your total window sill replacement cost, or an average of between $320 and $360 for an average-sized window. Materials are relatively inexpensive, but the process of removing the old window sill, cutting the new material to fit, and installing and sealing the sill is time-consuming. Labor costs can sit higher for tiled window sills, as these require replacing a wooden sill and then taking the extra step to install the tile.

Additional Cost Factors

The sill material, size, and labor costs are the most critical factors to consider to make sure you get an accurate estimate for the job. There are some other factors that can bring your total up or down, though.

Type of Window

The type of window you have can affect your window sill replacement costs. Sliding windows, for example, tend to be wider than they are tall and will require more linear feet of sill replaced. This comes at a higher cost than a smaller sill under a casement window, which tends to be taller than it is wide.

The linear feet of sill you need replaced will vary by window based on the average width, but bay windows and bow windows come with the most expensive sill replacement costs, as they have sills with a greater surface area inside. This demands more materials and higher labor costs, especially if you’re tiling the sill.

Window Location

An easily accessible window on the first floor will be the least expensive for sill replacement, while a window on the second floor will require ladders and safety equipment. Both of these factors make the job take longer, so window repair companies charge higher prices for the labor.

Number of Windows

Replacing a single window sill costs $400 on average, but you could pay less per window if you need multiple sills replaced at the same time. Most window technicians will offer per-window discounts if you guarantee them more work, and the trip fee, which your professional will only charge once, will be split between the windows.

Why You Should Hire a Window Repair Pro

Hiring your local window repair specialist to replace one or several window sills can cost anywhere from $150 to $1,000. While it may be tempting to try replacing them yourself, a pro will have the right tools and experience to complete the job efficiently without risky ladder or tool mishaps. 

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

From identifying deeper problems to ensuring your window sills are aligned properly, here are the benefits of hiring a window repair professional: 

• A pro can identify underlying issues such as window rot, damaged framing, and water intrusion, that a DIYer might miss. 

• Experts know how to seal and flash the sill correctly so your home stays protected from moisture and energy loss.

• A skilled repair person will measure, cut, and install your sills precisely to prevent drafts, leaks, and future warping.

• Licensed contractors often guarantee their work so that a warranty is in place in case a sill needs to be repaired or replaced again. 

If you want to DIY window sill replacement

Although it’s recommended to hire a professional to replace your window sill, there are some actionable steps you can prep so the job goes as smoothly as possible. 

• Move any furniture, plants, decor, or other items that could be in the way of your window. 

• Take down any blinds, curtains, or shutters to give the pro better access. 

• Wipe down the sill and the frame to get rid of any dust or debris. 

• Cover nearby furniture or electronics to protect them from potential dust from cutting or sanding. 

Window Sill Replacement vs. Repair

Window sill replacement costs an average of $400, while window sill repair costs between $200 and $300, depending on the repair needed. If you have cosmetic damage to the sill that isn’t threatening water intrusion, it will be more cost effective to carry out a repair. Otherwise, it’s best to spend a bit more on a full replacement to avoid problems in the future.

How to Save Money On Window Sill Replacement

Window sill replacement is a relatively affordable job, especially compared to the potential damage you’d have to fix from a leaking sill. However, there are a few things that can save you money that you may want to consider.

• Choose an affordable sill material. The materials for window sill replacement are inexpensive compared to the labor, but choosing a more affordable material, like vinyl or aluminum, will save between $25 and $75 per window, on average.

• Combine the work with other repairs. Window repair companies will charge a trip fee and a minimum of $100 per window sill you need repaired. Combining other repairs or window replacements while your pro is on-site can save you some money on additional trip fees.

• Finish the sill yourself. Window sill replacement is best left to a professional to ensure it’s installed properly, but you can do the cosmetic work to finish the job to save some money. For example, staining, painting, or sealing a wood sill yourself could save $25 to $50, and tiling a bay or bow window sill could save up to $100 in labor.

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. 

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