How much does it cost to replace basement windows?

Reviewed by Cristina Miguelez remodeling expert. Written by Fixr.com.

Whether your basement is finished or unfinished, you likely have at least one window. All basements require windows, and many have a mix to let in light, provide ventilation, or be used for egress. If your basement is finished as a living space, you need at least one egress window, more if the basement has a bedroom. Like the windows installed in your home, your basement windows can be inefficient, allowing heat transfer, or they may crack, warp, or become unusable, necessitating a replacement. Because there can be many types of windows used in a basement, there is a range of associated costs.

The national average cost to replace a basement window is $500 to $1,000, with most homeowners paying around $750 for a medium-sized prefab basement egress sliding window with a vinyl frame. This project’s low cost is $300 for a fixed prefab small glass block basement window with no ventilation. The high cost is $7,000 for a large custom fiberglass casement egress window with a new window well.

Price to Replace Basement Windows

Prefab vs Custom Basement Window Cost

Like all windows, basement replacement windows can be prefabricated, meaning they are readily available in set sizes or may be custom. In most cases, a prefab window will likely meet your needs. However, you may need a custom window if your basement is older and has an unconventional window size, or you want to install a custom egress window of a specific size or shape to match your home.

Custom windows are built to order, so they take longer to receive and cost more than prefab windows. They are most commonly used for homes with unique window sizes that cannot be changed. However, if you need an oversized egress or want a specific size or shape that is not readily available, a custom window can potentially meet your needs. Custom windows tend to be roughly 30% more costly than standard windows, but the actual range can be much larger, depending on the window. Below is a cost comparison for both material costs of prefab and custom basement windows for small to medium-sized windows.

Basement Window Cost by Size

Basement windows come in many of the same standard sizes throughout your home. The one difference is usually whether the window is above ground or not. Basement windows that are above-ground-only tend to be smaller. A small basement window must be a minimum of 20” wide and 24” high to meet current building codes. This can be a small hopper or egress window. You may also have some small fixed glass block “windows” that let in additional light, which may be 6” in height and 36” in width. These glass block windows must be installed with a 20” x 24” or larger window and cannot be the only window in the space. Medium-sized and large basement windows come in the same sizes as home windows, but they usually require a window well. This barrier holds back the earth from the window, creating a clearing. The well allows the window to be larger and let in more light. It also means the window can be used for egress comfortably, while a small egress window may be difficult to use, particularly when installed only above ground at the top of the basement wall.

The larger the window, the more costly it becomes because of the increased amount of frame material and glass. Below are the average material costs for prefab and custom basement windows of small, medium, and large sizes.

Average Cost of Basement Windows by Type

Basement windows come in many types and styles. These include small hopper and awning windows that may be installed for ventilation, glass block windows that can be installed for light, and a wide range of other windows that can be installed for egress, including casement, sliding, and sash windows. You need a minimum of one egress window in the basement unless you have an easily accessed egress door, and if you have a basement bedroom, it requires its own egress window. Many basements may have a mixture of windows, including some small hoppers or awnings mixed with one or more larger egress window types. Each style has costs and considerations, making one the right choice for your basement. Below are the average costs for the various basement windows in prefab and custom construction, based on the most common sizes.

Basement Hopper Windows

A replacement basement hopper window costs $100 to $250 for prefab. A custom hopper window averages $500 to $750. Hopper windows are common in basements because they can be installed without a well. They open from the top and swing inward. When shut, they are typically identical in looks, size, and style to awning windows. Hoppers cannot be used as egress windows because of how they open.

Awning Basement Window

The cost of a replacement awning window for the basement is $100 to $250 for a prefab window. The cost of a custom awning window averages $500 to $750. Awnings are small windows that open from the bottom and swing out. When shut, they look identical to hoppers. They are most typically installed for ventilation. They are common basements because they do not require a well. They are not used for egress because they do not open fully.

Glass Block Basement Window

The cost of a glass block window for a basement averages $100 to $300 for a prefab window. The cost of a custom glass block window averages $200 to $600. Glass block windows are frequently added at the top of a basement wall. They may be ventilated to let in air or may only let in light. These windows are not usually operational when installed in the basement and are mostly decorative. They are often combined with operational and egress windows in the basement for more light at a lower cost.

Single-Hung Basement Window

The cost of a replacement single-hung window for the basement is $100 to $400 for a prefab window. Custom single-hung windows average $500 to $800. Single-hung windows are a subtype of sash windows. They consist of two glass panes, and only the bottom sash or pane is operational. It slides up while the top remains fixed. These windows usually require a well when installed in the basement and may be used as egress.

Egress Basement Window

An egress basement window costs $100 to $800 for prefab or $500 to $2,000 for custom. This is for the window and not the cost of the associated well that may be needed for the window to work as an egress. Egress windows must be a minimum of 20” x 24” and are usually larger. You must have at least one egress window in the basement unless you have a separate egress, and you need at least one in a basement bedroom. They come in many shapes, styles, and sizes.

Sliding Basement Window

A prefab sliding basement window costs $150 to $700. A custom sliding basement window costs $700 to $1,000. Sliding windows are popular for basements. They can be smaller and may be installed without a well in some cases where the basement walls are tall enough. They can also be much larger, more usable, and accessible as an egress when installed with a well. They can also let in a lot of light. Sliding windows operate by sliding horizontally across the frame.

Casement Basement Window

A prefab replacement casement basement window costs $200 to $500. The cost of a custom window averages $800 to $1,300. Casement windows are taller windows that require a window well to be installed in a basement. They operate by opening outward, usually by a crank or other manual method. They can be installed singly or in pairs, but most sets installed together have a stile between them that can minimize the opening’s size. This is a good option for basements where you have the space for a well and want a taller, more narrow window.

Double-Hung Basement Window

The cost of a replacement double-hung window for a basement is $250 to $500. The cost of this custom-made window averages $850 to $1,350. Double-hung windows are another type of sash window like single-hung. The difference is that the two sections of window can move independently. This means the top section of the window can be lowered or the bottom section raised. Double-hung windows often have a tilt-in option that makes them easier to clean. They offer more options for ventilation, making them good for basements. Most require a well to be installed.

In-Swing Basement Window

The cost of an in-swing basement window averages $300 to $800 for prefab. Custom windows cost $900 to $2,000. In-swing windows are casement windows. They open into the home rather than out. If your basement window well is small, an in-swing window can allow it to open fully without impeding the well’s access. However, this window type needs interior clearance, so no furniture can be placed in front.

Basement Window Prices by Frame Material

Like all windows, those installed in the basement can have a range of frame materials. Vinyl, wood, and fiberglass are the most common, with aluminum and steel options for many homes. Each frame material dictates your replacement window’s cost and has different attributes making one better for your basement. You may want a specific frame material based on your home’s style, climate, and location. Below are the costs for the average basement replacement window using the most common sizes.

Vinyl Basement Window

Vinyl basement windows cost between $100 and $500 for prefab. Custom vinyl windows cost $500 to $900. Vinyl is one of the more inexpensive materials for window frames. It is moisture resistant and low maintenance, making it popular for basements. It does not insulate like wood or fiberglass, warps with heat, and cracks in extreme cold. It is best used in moderate climates.

Aluminum Basement Window

The cost of an aluminum basement window averages $100 to $500 for prefab. The cost of a custom aluminum window averages $500 to $900. Aluminum is another low-cost option that may be good for basements. It does not rust and resists warping, cracking, and melting, so it can last longer than other materials. It is also low maintenance but not as insulating as some materials. To better insulate your basement, you may need an aluminum frame with an insulating core.

Fiberglass

The cost of a fiberglass basement window is $200 to $800 for prefab. A custom fiberglass basement window costs $600 to $2,000. Fiberglass is often considered the gold standard in window frames by professionals. It is low maintenance, durable, and highly insulating. It is not impacted by moisture in a basement and can be installed in all climates. However, some larger windows can be very expensive with this frame.

Wood Basement Window

The cost of a wooden basement window averages $200 to $800 for prefab windows. A custom wood basement window costs $600 to $2,000. Wood is a good insulator that is popular for historical homes. It is not the best for basements due to the dampness of the space. Wood can warp and requires heavy maintenance to help it stay looking its best.

Steel Basement Window

The average cost of a steel prefab basement window is $250 to $800. The cost of a custom steel basement window averages $650 to $2,000. Steel is not a common material for window frames and is not a good fit for most basements. Steel can rust in high moisture levels. It is also not a good insulator and may be higher maintenance than other materials. Steel provides a strong frame, which can be good for security purposes.

Basement Window Cost by Brand

Many reputable window brands make basement windows. Some companies specialize in specific materials, while others offer lines for affordability or insulating properties. Some companies, such as Northview, Duo, Boman & Kemp, Monarch, and Wellcraft, make basement or egress windows designed for a window well. Because these companies specialize, they can help with finding the right fit or getting a window well to match.

Other companies, such as Jeld-Wen, Simonton, Milgard, Pella, Marvin, Harvey, Alside, and Andersen, make a range of window types. Many of these can be installed in basements, even if they are not specifically designed for this. If the window is not a traditional basement slider or hopper, you simply need to pair it with a window well. Other companies, such as Tafco, have specific lines of basement hopper and slider windows designed for this purpose and do not require wells. If your basement is finished and you want something more, companies like Loewen make high-quality windows that may give you a better style or appearance.

For those on a budget, consider companies like Alside and PGT, which specialize in vinyl windows that may be more affordable. Most companies offer standard warranties on their basement windows, but those that create windows just for this area may have better or longer warranties than those that manufacture windows for all areas. Below are the average costs for prefab windows from each company in the most common sizes.

Labor Cost to Replace a Basement Window

The labor cost to replace a basement window varies from $150 to $700 per window, depending on the window type and size. Hopper and awning windows typically cost $200 to $300 in labor to replace. Egress windows may cost between $200 and $700 per window, depending on the window type. Small hopper and awning windows are typically installed above ground, making them easier to replace. Larger and egress windows require getting into the window well, limiting space and raising labor costs. Small basement sliding windows usually have the lowest labor costs at $150 to $250 per window.

Larger windows and windows with more complex installations, such as casement windows with cranks or windows that need the entire frame replaced, have higher labor costs than smaller windows and replacements that can use an existing frame.

Replacing a basement window is much like replacing a window elsewhere. Windows that are easier to access have lower labor costs. Your costs can be much higher if you need to replace your window well, with a replacement window well costing $750 to $1,500 in labor. Costs for a new window replacement and new replacement well can reach $2,500 to $7,000, including all material and labor, depending on the window size and type. Replacing only the window has much lower costs of $500 to $1,000.

New Basement Window Cost in an Existing Wall

Expect to pay $1,500 to $3,500 per window if you add a new window to your basement. If you add a new window well at the same time, your costs may be $3,000 to $7,000. Adding a new basement window means cutting through your foundation. Installing a window for light or ventilation can be done in a few days. However, you need to cut into the foundation and excavate the soil and landscaping from outside of the foundation if you add an egress window to an existing wall. This can dramatically increase the installation cost, depending on how large the window and well are and the window’s style and material.

Cost to Add a Basement Window to a New Construction

Adding a basement window to new construction can have a range of costs depending on whether this is a small hopper or larger egress window. Total costs range from $500 to $5,000, depending on the window location. The foundation should be poured with an opening for the window, and egress areas should not be backfilled around the window. This helps keep costs down and allows more space for the new window installation. The landscaping can sometimes be designed for egress without needing a well. Sloping the land to the foundation or keeping it clear while filing in the space for support makes installing a window during construction easier than an existing basement.

Cost to Enlarge a Basement Window

Enlarging your basement windows can let in more light and air and creates the option of using them for egress if they are currently too small. The cost to expand a basement window varies depending on the window type, how much you are expanding, and whether you are making it an egress window with a well. Costs start from $500 to $1,000 to expand the opening, but if you are expanding the window size to make it an egress window, expect costs of between $1,500 and $3,000, including the additional excavation. This is because the window must be expanded, and the landscaping outside must be changed to allow for the window well placement. Your costs are lower if the window is only expanded for additional light. Shape, size, and window type also impact final costs.

Cost to Fill in a Basement Window

If you have an existing basement window and want it removed, it may be possible to fill it in. This process changes depending on your basement wall material type, cinder block or concrete, if the walls are finished, and if you also have a window well to fill. Costs for filing a window start at $60 per sq.ft. and may reach $200 a sq.ft. if you also need to fill in a well or finish the new wall’s interior. In most cases, contractors try to salvage a window. Most older windows can be replaced with newer, more functional versions with or without a well much more easily than the hole can be closed.

Convert a Basement Window to a Door Cost

If you are creating a basement apartment or finishing your basement and want to give it its own entrance, you can convert an existing window into a door, provided you can clear the landscaping from the area. Costs range from $2,500 to $10,000 to convert an existing basement window into a full egress door. This process involves cutting into your foundation’s concrete to enlarge the space, reframing it for a door rather than a window, and additional exterior excavation. Your window well must be removed, and the landscaping changed to create a walkway. This can be done in several ways, from adding stairs to gradually sloping the existing terrain. The existing window size and whether you already have a well impact your total costs.

Energy-Star Basement Window

Basement windows can run the gamut from basic to high-end with insulating properties and frames. This includes options for Energy-Star rated windows. Many windows not designed for basements can be installed in a basement if you have the right setup and window well. Therefore, you can purchase an Energy-Star rated casement window if you are replacing an existing basement casement window. There are also Energy-Star rated hopper and awning windows designed for basements. Costs for an Energy-Star rated basement window start at $200 to $800 each for materials and reach $2,000, depending on the window size, type, and frame.

Maintenance

Basement windows do not need much more maintenance than other windows. However, many basement windows can leak. This is because of how they are installed in the foundation and their position to ground level. Part of your ongoing maintenance should be checking frequently for leaks. You may need additional caulking around the window to help stop leaks. Otherwise, regular maintenance includes inspecting the window, cleaning, removing old paint, and repainting wood windows.

Enhancement and Improvement Costs

Basement Window Well Installation

A window well costs $1,500 to $7,000 to install. The well helps create an egress window in your basement. Depending on your well’s height, depth, size, shape, and landscaping, this could be a simple excavation or a much larger project. Some pour concrete for their well and install a cover over it. Others only hold back the soil with a small retainer to help the well keep its shape. Speak to your contractor about the best way to create a window well for your basement window.

Flood-Proof Basement Window

You may want to install a flood-proof basement window if you live in a flood-prone area. This is usually a hopper, sliding, or awning window with a very tight seal. These windows are designed to shut securely so that no water can get through, no matter how much pressure builds on the outside. As a bonus, most are also burglar-proof. They have starting costs of around $300 to $500 for materials.

Finishing Basement Windows

If you have a finished basement, you may want to finish the windows on the interior. This can include trim, a window sill, or other surface materials. Typical costs reach $700 to $1,400 per window to finish the interior of a basement window with new trim, sill, and paint.

Additional Considerations and Costs

• Permits. Permits may be required for basement window installations in some states. Ask your local municipality about which permits may be necessary.
• Licenses. Ensure your contractor is licensed and insured in your state. Speak to your local municipality about which licenses may be required.
• DIY. This job cannot be done DIY. Basement windows need specific installation to ensure they are watertight and do not leak.
• Home value. Replacement windows add value to your home regardless of where they are installed. Adding an egress window to your basement may increase the value even more.
• Resale value. Replacement windows generally have a 67% ROI, which is true of basements.
• Payment plans. Some window companies offer payment plans to keep costs down. Interest rates and payment plans may be subject to credit approval. Speak with the company for more information.
• Warranty. Windows may come with a warranty, and your installer may also warranty their labor. This varies by brand and placement, so speak with your installer about available warranties.
• Residential code requirements. Building codes dictate the need for egress windows and the smallest size of basement windows. If you are unsure about which codes may impact your project, speak to your local municipality.
• Placement. The window size is much more limited if you install a basement window above-ground, but the costs may be lower without excavation.
• Storm windows. Storm windows are less common in basements because the window well helps create a wind and thermal break. You can install them if necessary, but you cannot put them over egress windows.
• Glass types. Basement windows come with many of the same glass types as other replacement windows. This includes single and double-panes, insulating options with gas-filled panes, and laminated safety glass. Adding specialty glass to your basement window may increase costs.