You can create a window in many ways, whether to the outdoors or as a partition inside. While many people opt for solid glass or operational windows, sometimes a stationary window makes the most sense. In this case, consider glass block windows for your home. Glass block windows are made of individual thick glass bricks or squares. They come in several sizes, transparencies, and styles and can be found in ready-made windows or separate blocks for custom installations. They can provide a unique look and style to any area.
With many sizes and styles, glass block windows have a wide range of associated costs. The national average cost range for installing glass block windows is $600 to $1,500 per window, with most homeowners paying around $800 to install a standard 36” x 48” bathroom window with privacy glass. This project’s low cost is $300 for an installed 24” square prefabricated basement window. The high cost is $5,000 to install a custom floor-to-ceiling 8’ long window partition between two rooms.
|Glass Block Window Prices|
|National average cost||$800|
Block windows essentially look the same once they are installed. They are made of individual pieces mortared together into a single window. How they are made, however, varies depending on the installation type. For most standard window sizes, you can purchase ready-made glass block windows. These come in a solid piece, ready for installation. They may have a slightly higher cost for the material but cost significantly less to install because much less labor is required. In many cases, this is a good choice if you are replacing an existing window or adding a new window of a standard size.
Glass block windows can also be used to create custom spaces and partitions, including glass block walls, floor-to-ceiling “windows” dividing a space, or to give you a uniquely sized or shaped window. In this case, you purchase the individual blocks, and your installer pieces them together on-site. This has a slightly lower material cost but a much higher installation cost because custom windows tend to be much larger or have more complex shapes and patterns than what is available ready-made. Below are the average costs per window to install prefabricated or custom glass block windows in your home.
|Window Type||Unit Cost (Installed)|
|Prefab||$300 - $1,500|
|Custom||$600 - $5,000|
Prefabricated glass block windows cost between $300 and $1,500 installed. These windows come in mostly standard sizes designed to fit in place of the average window in your home. They are most commonly found in basements, bathrooms, foyers, entryways, and other areas where operational windows may not be necessary but where you want to add some light and/or privacy. Prefabricated glass block windows cost more per square foot for the material than custom but are much less expensive to install. Because the window is a solid unit, it installs much more easily than a custom window made of individual blocks. These windows can be found in many sizes at a typical big box store.
The cost of a custom glass block window ranges from $600 to $5,000 installed. Custom glass block windows are built on-site using individual blocks of glass. They are usually larger and may include curves, patterns, differently sized blocks, and other features that make them stand out. If you want to build a glass wall between your toilet and shower or a floor-to-ceiling glass block window between your kitchen and dining room, you likely need a custom installation. Likewise, you need a custom installation if you want that glass wall to curve. The more complex the pattern or installation, the higher your total costs.
Glass block windows can be used in many areas in and around the home. They can have a ventilated section or be solid, and they may be framed or unframed, depending on the placement and type. When choosing prefabricated windows, many sizes may not be available outside of the standard. The blocks are 5.5”, 5.75”, 7.5”, or 7.75” in width and height. For this reason, while you may be assuming the window is 24” square, it is more likely to be 23.5” square. The difference is made up with the mortar and mounting around the perimeter. These exact measurements vary from manufacturer to manufacturer, but most are slightly smaller than the size they are intended to fit.
Because the blocks are normally found in 6” and 8” nominal squares, your window sizes must be in increments of 6” or 8” to fit. There are some half-blocks available if you choose a custom installation, which can give you a single row of 3” or 4”, nominally, to help the window fit the space more easily. Keep in mind that blocks are often sold in packages of 10 if you purchase them individually. So, round your costs up to the nearest package when calculating your material costs.
|Window Size||Prefab Cost (Installed)||Custom Cost (Installed)|
|12” x 24”||N/A||$365 - $1,200|
|16” x 32”||N/A||$365 - $1,200|
|24” x 24”||$250 - $900||$430 - $1,400|
|24” x 32”||$300 - $1,250||$430 - $1,400|
|36” x 36”||$400 - $1,600||$550 - $2,800|
|36” x 48”||N/A||$550 - $3,000|
|48” x 48”||$750 - $2,000||$625 - $3,900|
When it comes to assembling your window, this can be done using a few methods. You can use a prefab vinyl-framed window. You can also create a custom vinyl-framed window, an unframed prefab window mortared in place, or an unframed window wall that requires mortar and rebar between the blocks for stability. Vinyl-framed windows usually come with the frame intact. This makes for the easiest installation because the frame fits into the open cavity easily and makes a tight seal. You can have a vinyl frame created on-site for some custom windows, but this tends to be less common.
If you are not using a frame, the window is mortared directly in place. You can purchase prefab windows without a frame or have them custom-made using mortar between the blocks and around the edge to fit. Finally, you need supportive rebar and mortar between the glass blocks if you are constructing a much larger glass block window or a window wall. This helps give the wall strength and stability for long-term use. How the blocks are assembled and installed can impact your project costs. Prefab framed windows are the least expensive to install, while custom glass block walls requiring rebar cost the most. Below are the average costs for the different assembly methods per square foot for prefab and custom installations using the various assembly methods.
|Assembly Method||Prefab Cost per Sq.Ft. (Installed)||Custom Cost per Sq.Ft. (Installed)|
|Unframed Mortared||$25 - $75||$50 - $150|
|Vinyl Framed||$30 - $80||$60 - $160|
|Mortared and Rebarred||N/A||$80 - $200|
The cost to install prefab mortared glass block windows averages $25 to $75 a sq.ft. The cost to install a custom mortared glass block window averages $50 to $150 a sq.ft. This latter cost includes assembly of the blocks to form the window plus the installation of the window into the wall. Mortared glass block windows are some of the most common kinds. The mortar is usually a blend of Portland cement but may include other materials, such as silicone or latex for flexibility. This mortar may be white, gray, or other colors.
The cost to install vinyl-framed prefab glass block windows averages $30 to $80 a sq.ft. The cost to install a custom glass block window with a vinyl frame averages $60 to $160 a sq.ft. This latter includes the assembly of loose materials and the final installation in the wall. Vinyl-framed glass block windows are popular for exterior walls. They help create a tighter seal inside the wall, and some allow the window to open by hinging the glass blocks inside the frame. The glass blocks can be swung out or in, while the frame remains in the wall, creating a functioning window.
The cost to create a custom mortared and rebarred glass block wall or window averages $80 to $200 a sq.ft. These materials are always custom and not available as prefab products. This assembly style is used for very large windows and glass block walls. The rebar is laid into the mortar between the rows of glass. It is not obvious once the installation is complete, but it adds strength and stability to the glass. This can make the wall safer and longer-lasting. If your glass wall is curved or exceptionally long or tall, rebar should be added to ensure it keeps good integrity as it ages and the home or building settles.
Most glass blocks on the market measure 8” square, nominally. This means the blocks measure 8” square when assembled with mortar, but they measure around 7⅞” square alone and unassembled. Some companies also produce a 6” nominal block or 5⅞” square. These blocks are often used for smaller installations and decorative patterns. In most cases, the blocks are 3⅞” (4” nominal) thick, but some thinner blocks may be 3” thick. These latter are relatively rare because thinner blocks are less stable.
A few companies make 4” nominal blocks, but these are relatively rare and may require special ordering. These blocks measure 3⅞” square, with a thickness of roughly 3”. The exact dimensions of the blocks can vary by ½” by manufacturer. For this reason, if you purchase multiple types of blocks labeled 8” ensure they come from the same brand and line. Otherwise, they may not be the same size and may not be able to be used in the same installations. Always check the exact measurements even within one brand if you move between styles to ensure the sizes match.
Some colored decorative blocks may be ordered in other sizes, but this is extremely rare and must be ordered as a bespoke project, such as you need to order hundreds of blocks in a different shape or size to create the commission. Because these blocks are bespoke, costs depend on the size, color, and number ordered. For blocks of standard sizes, you can typically find them easily at many box stores in a range of styles. Below are the average costs for the most common glass block sizes.
|Size||Costs per Block (Materials Only)|
|8” x 8”||$5 - $25|
|6” x 6”||$10 - $30|
|4” x 4”||$15 - $40|
When you create a glass block window or wall, you may need a few block types. While a prefab window comes assembled with all the various corner and edge pieces necessary, a custom window must have these pieces on-hand and ready for assembly.
For example, while a framed window only requires the standard blocks, a window wall may need different pieces like blocks to finish the top or side edges. If the wall curves or changes direction, you need corner pieces to make the transition. Use a linear end block if you are ending the glass wall and want a smooth finish. This block fits in with other blocks on two or three sides but has a finished side or top and side to stand alone.
You can use a curved end or double-curved end if you want something more decorative, depending on if the side or top and side are exposed. There are also sharp and rounded angles if your wall turns a corner. Most blocks you use are standard square blocks. You do not need these other pieces if this is a window. Only interior glass block walls that do not terminate at another wall or ceiling need these specialty pieces. Below are the average costs per block for the various types and pieces.
|Type||Costs per Block (Materials Only)|
|Standard||$6 - $25|
|Linear End||$30 - $50|
|Curved End||$30 - $50|
|Sharp Angle||$40 - $60|
|Round Angle||$40 - $60|
|Double-Curved End||$50 - $70|
|Double End||$50 - $70|
Despite their name, not all glass blocks are made from glass. While many are, some are made from acrylic, a type of lightweight plastic. While glass blocks are durable and attractive, they are also heavy and not as easy to cut and manipulate. For this reason, some installations do better with acrylic blocks, which are lightweight and can be cut to accommodate a vent. Acrylic blocks can scratch and discolor while glass resists these changes. Glass blocks can offer good insulation that acrylic cannot. For this reason, acrylic glass blocks are more often used indoors than in true window situations. Below are the average costs per block for both materials. These costs are for the individual blocks - not for a prefabricated window.
|Material||Cost per Block (Materials Only)|
|Glass||$6 - $12|
|Acrylic||$12 - $20|
Clear glass block windows cost $6 to $12 per glass block. They are made from a mixture of limestone, soda ash, sand, and cullet. This mixture is heated to extreme temperatures, melted, and poured into shaping molds. They have been a popular choice for basements and bathrooms, but homeowners are also adding them to bedrooms and living rooms. They offer superior thermal insulation, making them a great choice for exterior walls. However, they do not offer natural ventilation because they are tightly sealed, and it is difficult to fit a vent into their surface.
Acrylic glass blocks range between $12 and $20 per block and are dependable for light-weight block situations. Since these plastic-based blocks are not as heavy as glass blocks, they can be cut or modified to fit a vent into the window. This allows you to use the blocks to help vent shower transoms or dryers. Because acrylic is lightweight and easily manipulated, they are more common for building shower walls and other interior applications than glass blocks. Acrylic blocks are normally sold loose and installed on the spot rather than sold in prefab windows.
Glass blocks come in many finishes, impacting the level of translucency or opacity the blocks have. Many can be made of clear glass, which lets in the maximum amount of light. These clear glass blocks may have a waviness, which provides privacy without sacrificing light. Other blocks may be translucent but not completely transparent, while others may be frosted or opaque, letting through little-to-no light but offering a lot of privacy.
Most blocks are at least translucent, allowing in a good degree of light. Even frosted glass allows some light to pass, which can add a light glow to the room without direct light or sunlight. These blocks tend to be the least common, with clear and semi-transparent glass being the most common. Below are the average per-block costs for glass blocks with varying levels of opacity.
|Opacity||Cost per Block (Materials Only)|
|Clear / Transparent||$6 - $10|
|Semi-Transparent / Translucent||$6 - $15|
|Frosted / Non-Transparent||$10 - $20|
|Colored||$12 - $25|
The cost of clear or transparent glass blocks is $6 to $10 per block. Clear blocks allow the most light to pass through. They may have a smooth finish or a slight ripple or wave to the glass, obscuring the view without sacrificing light. These blocks are the most popular in basements, some foyers, and in areas where you want to maximize the amount of light coming in. The plainer the glass, the less costly the blocks. The more wavy or ripple the glass has, the higher the cost.
Semi-transparent or translucent glass blocks cost between $6 and $15 per block. These blocks let some light through but are more difficult to see through. They may have a surface texture that allows the passage of light but does not allow you to see through the glass. Or, they may be tinted a color that allows light to pass through. If the blocks are colored, it is generally a very light tint, not a full deep color that saturates the glass. These blocks are good in bathrooms, separating rooms, and other areas where you may need more privacy but do not want to sacrifice light.
The cost of frosted or non-transparent glass blocks is $10 to $20 per block. In this case, little-to-no light comes through the block. The blocks often have a slightly rougher surface texture and a blue/green color or tint because true glass is green due to the iron content. The lack of light passage often emphasizes this color. Frosted glass does not let light through like other types of glass blocks do, but it may glow or appear lit from behind if there is a strong light or bright sun on the other side. This is a good privacy glass and fine for very bright areas that do not need to maximize light. Sometimes, a few frosted blocks may be mixed in with other blocks to create a pattern without sacrificing light.
Colored glass block prices cost around $12 to $25 per block. Colored glass blocks come in an incredible range of colors and translucencies. Some have a slight tint of color while remaining otherwise clear. Others have a bold solid color that is translucent but not transparent. Colored glass blocks can be found in nearly any color, from light pastel tints to bold reds, greens, blues, and yellows. The colors can be used singularly or mixed to create a unique pattern and design.
In addition to different finishes and opacities, glass blocks also come in several patterns and styles. Some of these styles describe the appearance of the glass - it may be wavy, grooved, or rippled to help obscure images while maximizing light. Or, the glass may be given a different texture, such as a diamond pattern, frosting, or leathering, to add more privacy and interest to the design. In some cases, you may want to mix styles within one window or wall to create a unique pattern. Other times, you may want to keep to a single style for a cohesive look.
Most glass blocks can be found in different tints or colors in the various styles. However, some finishes like leather are rare and somewhat proprietary. You may find only one or two manufacturers that produce that finish, so your sizes and other characteristics may be more limited. Prefab windows may only be found in a more limited number of styles. Below are the average costs per block for the different styles available. Most are sold in groups of 10 or more rather than by the individual block.
|Style||Cost per Block (Materials Only)|
|Clear||$6 - $10|
|Alpha||$6 - $10|
|Wavy||$6 - $15|
|Ice||$6 - $15|
|Diamond||$10 - $20|
|Frosted||$10 - $20|
|Leather||$10 - $20|
Clear glass blocks cost between $6 and $10 a piece. These blocks transmit the most light. They also offer the clearest view and do not offer much privacy. The blocks may have a slight green tint due to the presence of iron. You can purchase clear blocks with different colors or tints, increasing costs. These blocks work well for small windows and dark areas where you want to maximize light but are not worried about privacy.
The cost of Alpha glass blocks averages $6 to $10 a piece. Alpha blocks are made of a clear block with a rippling circle in the center. They offer the maximum amount of light without privacy and only minimally obscure images when looking through the blocks. Rather than being used as a privacy block, the Alpha style is mostly used for aesthetics. They are more interesting to look at than clear glass blocks with a repeating pattern of circles.
Wavy blocks cost $6 to $15 per block. Wavy blocks are a fairly common pattern for windows and glass walls. They allow the maximum amount of light to pass through but obscure images by distorting them. It does not offer true privacy, but it can provide better privacy than standard clear blocks for small bathroom and basement windows. These blocks are also popular for showers and interior glass block walls. Like clear blocks, they may have a slight green tint and are available in other tints and colors.
The cost of an ice-style glass block averages $6 to $15 a piece. Ice-style glass blocks still let in a fairly large amount of light, but they are more translucent than transparent with better privacy and obscuring properties. The entire surface is textured in appearance and to the touch. This helps the blocks offer the most amount of privacy without sacrificing light. These blocks are available in a few tints but not as many as other styles.
Diamond-style glass blocks average $10 to $20 a piece. Diamond finishes are great for letting in light while offering maximum privacy. The entire surface of the blocks is etched in a pattern of criss-crossing lines, which form small squares or diamonds, depending on the manufacturer. This pattern is made on clear glass, so light still passes through the glass easily. However, the many crossing lines completely obscure images on the other side. This makes these blocks great for larger bathroom windows or shared bathrooms where a privacy wall may be required.
Frosted glass blocks cost $10 to $20 a piece. Frosted finishes are a good choice if you want total obscurement and privacy but do not need much natural light. The frosted finish creates a nearly opaque finish on the glass. Because of the texture and lack of reflection, these blocks tend to be more obviously tinted green in color from the iron in the glass. They may appear as though they are back-lit or glowing if there is a light source on one side, but they do not contribute to the room’s ambient light. This makes them a good accent and privacy choice.
Leathered glass blocks cost $10 to $20 a piece. This is a fairly rare finish. Only a few companies create this finish, so you may be more limited in size and color. This finish is a little softer than a true frosted finish. It obscures the image through the glass by creating a texture on the surface, but it is not quite as opaque. This lets a little bit more light through but not enough to truly call the finish translucent. The green color may be a little softer on leathered as opposed to frosted.
There are many reputable manufacturers for glass blocks and glass block windows in the U.S. Many of these companies produce a range of products, including glass with different finishes, colors, and edge profiles to create the ideal window or glass block wall for your home.
Some companies like Seves and TAFCO are readily available at most big box stores. Their materials are sold in cases for standard blocks and by the piece for edge treatments. Other companies like Pittsburgh Corning - one of the first companies to produce glass blocks in the U.S. - supply all parts of the glass and windows to create a range of finished results. These include things like glass block window kits that can be installed DIY and specialty materials and colors.
If you are looking for a company to handle glass blocks and glass block windows, consider Quality Glass Block & Windows. They offer both the blocks in a range of styles and sizes but also many standard-size windows ready to be installed. When looking for truly innovative materials, consider Mulia. They offer plain glass blocks available at most big box stores and a full range of specialty blocks. These include unique colors and finishes because Mulia also produces a range of other glass items, such as bottles and decorative glass housewares. Below are the average costs per block for the standard and most common glass block types sold from each company.
|Brand||Price per Block (Materials Only)|
|TAFCO||$6 - $10|
|Pittsburgh Corning||$6 - $20|
|Seves||$8 - $12|
|Quality Glass Block & Window||$8 - $20|
|Mulia||$8 - $20|
The labor costs to install a glass block window varies depending on certain features. Installing a prefab window with or without a frame costs between $15 and $30 per sq.ft. for labor. Labor costs for installing a glass block window with a custom build and installation start at $30 per sq.ft. for windows. Larger installations that require edging, rebar, and patterns can have labor costs as high as $150 per sq.ft. The more intricate the project, the higher the total labor cost. Installing a vinyl-framed prefab window is usually a simple process that only takes a few hours. Building a custom glass block wall that curves and changes color or patterns is a time-consuming process that can take several days. For this reason, your labor costs can be very different, depending on the installation type. Below are the average labor costs for prefab and custom installations.
|Installation Type||Labor Cost|
|Prefab||$150 - $1,000|
|Custom||$300 - $4,500|
If you have an existing glass block window that needs to be replaced, you could have two sets of costs, depending on if you want to keep and reuse the blocks. If you do not want to keep the blocks, the old window can be taken out easily by removing the sealant over the mortar, taping the glass to avoid shattering, and then breaking it into pieces. This has a cost of $200 to $400 per window plus the cost of the new window for an average cost range of $800 to $1,900.
However, if you want to keep or reuse the glass blocks, removing the old window or individual blocks is much more time-consuming. However, it can be done at a cost of $500 to $1,000 per window. The benefit of this is if only a few blocks are cracked, you can reuse the others, lowering your total cost, waste, and environmental impact. Or, you can reuse the blocks elsewhere in another project, saving you money on that project. If you do not reuse the blocks in the same window, your replacement costs are $1,000 to $2,500 per window. If you reuse the blocks, your costs may be lower, depending on the block’s condition and how many you can reuse.
If you have existing standard windows you want to replace with a glass block window, you have removal and disposal costs of the old window in addition to the installation of the glass block window. Standard window removal costs between $100 and $300 per window for most standard windows. Very large windows or windows with custom settings may cost more to remove. The total cost to replace an existing window with a glass block window is $700 to $1,800, including removal, disposal, and the installation of the new window.
Glass block windows can be installed in any area in and around the home. They can be used to create fixed windows, add privacy without compromising light, or build partitions and walls in spaces like bathrooms or basement bars. Each location may have a range of standard sizes used to create these windows or window walls. This results in a range of associated costs, depending on if you choose a prefabricated window or a custom one.
While window installations can be prefab or custom, depending on the size, all wall installations are custom and built on-site with loose blocks, mortar, and usually rebar for support. Below are the average costs to install different window types - prefab or custom - in various locations in and around the home. The costs are based on the most common sizes used in each location.
|Location||Prefab Cost (Installed)||Custom Cost (Installed)|
|Basement Window||$300 - $600||$600 - $1,200|
|Garage Window||$300 - $1,500||$600 - $3,000|
|Bathroom Window||$400 - $1,000||$800 - $2,000|
|Bar Front||N/A||$2,000 - $3,000|
|Wall||N/A||$2,000 - $5,000|
|Shower Wall||N/A||$2,000 - $5,000|
Glass block prefab basement windows cost between $300 and $600. Custom basement windows cost $600 to $1,200. Provided you have at least one egress window or door already installed in your basement, glass block windows can offer some additional light and style to the space. Glass block basement windows can be vented or unvented and come in several sizes. Many are just one block high and about 2’ to 3’ in length. They are designed to let more light into your basement while still offering some privacy. These windows cannot be used for egress, which is why you must have another form of egress in place.
The cost to install a prefab window in your garage ranges from $300 to $1,500. The average cost to install a custom glass block window in your garage ranges from $600 to $3,000. Most garages do not have windows included in the design. Therefore, there is no standard size for a garage window. You can install a small 12” x 24” window or a large 4’ x 6’ window. Using glass blocks for this project can help maximize light while obscuring the interior. If you use the garage as a work space, adding a glass block window can increase ambient light, while keeping people from looking in.
The cost to install a prefab glass block window in a bathroom averages $400 to $1,000. The cost of installing a custom glass block window in a bathroom averages $800 to $2,000. Bathroom windows come in a range of sizes, beginning with 12” x 24” for small bathrooms and increasing to 2’ x 4’ for some larger spaces. Glass block windows in the bathroom can allow you to get maximum light and privacy if you use an obscuring glass. Some prefab glass windows may come with a vent, allowing steam to escape. If you use a glass block transom for a steam shower, you need a vent installed in the glass.
The cost to build a custom glass block bar front is $2,000 to $3,000. This is just the front of the bar, so you need a frame of support to install a countertop on the bar to make it fully functional. These costs are for building the glass block wall front to the bar, not to build the entire bar with a countertop. Your costs could approach $3,000 to $8,000, including the counter, sink, plumbing, and lights. Glass block bar fronts are attractive and can be lit from behind to create a stunning display that adds to the ambiance. These blocks can be clear or any finish because they are not designed for privacy.
The cost to build a glass block wall averages $2,000 to $5,000, depending on the wall size and scope. Glass block walls can be used for a range of purposes. You can build a privacy wall using obscuring glass to separate a toilet from the shower area in busy bathrooms. You can also build glass wall partitions to divide a previously open floor plan, create a partition between a kitchen and bathroom, or for decoration. Glass block walls can be straight or curved, half-walls, or extend to the ceiling. They can be made of any glass block and built in any color or pattern, depending on their area and your needs. By creating glass block walls instead of solid walls, you can increase the amount of ambient light while still offering privacy.
The average cost of a glass block shower wall is $2,000 to $5,000. Glass block shower walls are always custom-made. They may be a single wall with a doorway at one end, two walls with a doorway, or a curved or angled wall wrapping two or more sides of the shower with an opening for the entrance. Glass block showers may be made of clear glass but are usually made with obscuring glass. This means the shower still gets plenty of light while offering some privacy for the user if this is a shared space. Glass block shower walls are usually used as splash guards, meaning the shower does not normally have an operational door but only an opening.
Some prefab glass block windows are eligible for the Energy Star seal. No custom block glass windows qualify as Energy Star rated. Even prefabricated glass block windows are unlikely to be Energy Star certified. Only those companies using acrylic blocks that are molded, rather than individually pieced and have undergone testing, are eligible for the seal. Most standard glass block windows do not meet these requirements. Costs for the windows begin at around $600 to $900 for the window only, and sizes are limited.
Glass block windows offer many benefits to the area where they are installed. Depending on the glass type, a glass block window can let in light while adding personality. Or, you can increase the ambient light of a space while obscuring the view so that the users have privacy without hanging curtains or other window coverings to block light. Glass block windows are much thicker than standard glass windows, meaning they are better at insulating. This can give you better results in efficiency and a more aesthetically pleasing window.
Block windows are usually more expensive than plate-glass windows, however. Most are also non-operational with only a select few types mounted in frames that allow the window to swing open. This means the windows cannot allow air or natural ventilation into the space. If you need a vent in the window, one can be added, but this detracts from the window’s appearance.
Glass block windows are more energy-efficient than standard windows. A glass block window of normal thickness - roughly 4” - has an R-value of 1.96. In contrast, a standard double paned window has an R-value of 1.15. When properly sealed and installed, glass block windows have few-to-no air leaks around the edges. This is because the glass is non-operational and does not have moving parts where the seal can break easily. For this reason, glass block windows are often more comfortable to be near and more energy-efficient.
While glass tiles and glass blocks are available in similar shapes and sometimes colors and finishes, these are different materials designed for different things. Glass blocks are designed to fit together to form a window or wall that stands on its own. While the blocks are mortared together, they do not require a backer or substrate to adhere to.
Glass tiles are thinner pieces of glass that must be adhered to a backer - usually cement board. The tiles are adhered using a white latex additive thinset mortar that has had all key-marks smoothed out. Between the tiles, sanded grout is needed to fill the gaps and prevent chipping of the tiles’ edges. Glass blocks create walls and windows, and glass tiles add color, depth, and interest to an existing wall. They cannot be used interchangeably.
An alternative to using a glass block window is to use a standard window that uses a pane of glass or a panel in very large windows. Costs are not always easy to compare between the two because the size, thickness, and placement are different. Most glass block installations are made from individual blocks on-site, while standard glass windows are sold as-is and ready for installation at all times.
A good example of a glass “panel” window would be a picture window, which uses a large single panel of glass in a frame without individual panes. This window type provides an unimpeded view of the outdoors, while a glass block window of the same size breaks the view. However, a picture window would only give you a single glass type, while a glass block window could offer options for style and color.
Of the two installations, assuming an average size of a picture window of 6’ x 4’, the glass panel would be considerably less expensive than the glass block window. Below are the average costs for a 6’ x 4’ installation of both types.
|Window Type||Unit Cost (Installed)|
|Glass Panel||$500 - $1,300|
|Glass Block||$720 - $3,600|
When installing a new basement window, you have many choices. One of these is to install a glass block window, while another popular choice is to install a vinyl window. Vinyl basement windows are typically operational. They may open for ventilation or be large enough to act as an egress window, depending on if this is a well to allow for adequate movement and space.
Glass block windows used in basements are fixed. They are often smaller and designed to let more light into your basement. They are not designed to be used as an egress, and you must have an egress installed. Many people choose to install long, thin glass block windows near their basement ceilings as a way of bringing in more ambient light to the basement while still offering some privacy. These may be used in conjunction with a vinyl basement egress window or windows. Because vinyl windows are designed to be used for egress, their costs are typically much higher than a glass block window, which cannot be used for egress. Below are the average costs for installing both windows in a basement.
|Basement Window Type||Unit Cost (Installed)|
|Glass Block||$300 - $1,200|
|Vinyl||$900 - $3,650|
You can light your glass block walls with an LED ribbon between the rows of blocks or behind the blocks. Depending on where your wall is, this can be a great way to liven up a workspace or add mood lighting. This adds approximately $50 to $300 to the project cost, depending on the window size and how many lights you add.
You may want a window with a vent because glass block windows are naturally tightly sealed and allow no ventilation. Some prefab glass block windows come with a vent already installed. These have starting costs of around $100 to $600 per window and let some air and ventilation through. They are good for bathrooms and installation near dryers.
Your total installation costs vary based on several factors, such as the window type and size and placement. The national average cost range for installation is $600 to $1,500.
When compared to the cost of a standard glass window of the same size and shape, yes, glass block windows can be more expensive. They are also thicker, offer privacy, and are more energy-efficient than standard windows.
Yes, glass block windows insulate better than standard paned windows. They have an R-value of 1.96. They are also non-operational and have a tight seal around their edges, meaning they have little air transfer, making them more comfortable.
Yes, glass block windows are completely sealed and waterproof. This makes them ideal for bathrooms, basements, and outside wall installations.
This depends on the window and glass type. Some companies manufacture security glass, which can withstand hurricane-force winds. Because glass blocks are generally 4” in thickness, many can withstand high winds. Speak with the retailer or manufacturer to find out the tolerances of the window.