Glass block windows aren’t especially popular in homes, but they have some advantages over regular pane windows. The thick glass provides increased insulation and security, obscuring the view from outside without blocking natural light. These windows are a good option in bathrooms and basements, especially for ranch-style homes.
Key Takeaways
- Glass block windows typically cost between $250 and $3,900, with the national average of $720 per window depending on glass size, type, and customization level.
- Standard glass blocks range from $5–$25 for 8-by-8-inch blocks to $15–$40 for 4-by-4-inch blocks, with specialty blocks for corners and curves costing $30–$70.
- Prefabricated glass block windows cost $150–$1,000 per window installed, while custom glass block windows require more labor and range from $300–$4,500 per window.
- According to This Old House’s 2025 survey of 1,000 homeowners, glass block windows averaged $1,437 per window — making them one of the more affordable specialty window options compared to bay windows ($1,513) or custom shapes ($1,580).
Get Estimates from Window Experts in Your Area
Compare quotes from local pros
*We averaged cost figures in this article from Angi, Home Advisor, and Fixr.
What Are The Benefits of Glass Block Windows?
Glass block windows offer several benefits compared to other quality replacement windows.
Glass block windows have a particular look that can create a spa-like bathroom feel. They can also add visual interest in less-decorated areas such as basements and garages.
Glass is an excellent insulator, and glass block windows don’t open which prevents air leaks and drafts. This means your home’s HVAC system won’t have to work as hard.
Glass block windows offer privacy by obscuring the glass view without blocking light. This makes them useful in low-light rooms or areas where window treatments aren’t practical.
It’s far harder to break through a thick glass block than a single-pane window, making glass block windows more secure.
What Factors Affect Glass Block Window Installation Cost?
Your total project cost is primarily determined by the following factors:
- Size: The bigger the block and window, the more you’ll pay.
- Block type: The blocks’ finish and opacity helps determine price.
- Block style: Specialty shapes cost more than standard square blocks.
- Brand: Some glass block manufacturers charge more than others.
- According to This Old House’s 2025 window survey, glass block windows averaged $1,437 per window, placing them in the mid-range of window costs. The survey found that glass block installations typically fell within a $400–$2,200 price range, with size and customization being the primary cost drivers.
Cost by Glass Block Size
Glass blocks come in standard sizes of 6-by-6 inches and 8-by-8 inches. You may see 4-by-4-inch blocks, but they’re much less common and thus cost more. Here are the average cost ranges by block size.
| Block Size in Inches | Cost Range | Average Cost |
|---|---|---|
| 4″x4″ | $15–$40 | $275 |
| 6″x6″ | $10–$30 | $375 |
| 8″x8″ | $5–$25 | $675 |
- According to This Old House’s 2025 survey of over 1,000 homeowners, the most common price points for individual window purchases ranged from $100 to $500, with significant clusters at $100 (59 responses), $200 (73 responses), $250 (72 responses), and $500 (82 responses). While glass block windows typically fall within this range, custom installations can push costs higher.
Larger glass block windows cost more to install than smaller ones. Prefabricated glass block windows come in standard sizes and are more affordable than custom options.
| Window Size in Inches | Prefabricated Cost | Customized Cost |
|---|---|---|
| 12″x24″ | N/A* | $365–$1,200 |
| 16″x32″ | N/A* | $365–$1,200 |
| 24″x24″ | $250–$900 | $430–$1,400 |
| 24″x32″ | $300–$1,250 | $430–$1,400 |
| 36″x36″ | $400–$1,600 | $550–$2,800 |
| 36″x48″ | N/A* | $550–$3,000 |
| 48″x48″ | $750–$2,000 | $625–$3,900 |
Installation labor costs also impact your total project price. This Old House’s 2025 survey revealed that the most common installer rate was $50 per hour (reported by 275 respondents), followed by $100 per hour (157 respondents). Glass block installation typically requires specialized skills, which may command rates at the higher end of this range.
Cost by Glass Block Type
Most glass block walls and windows have standard square bricks, but you’ll need specialty blocks for window edges, corners, and wall curves or ends. Prefab glass block windows include these additional blocks.
| Glass Block Type | Cost Range | Average Cost |
|---|---|---|
| Standard square | $6–$25 | $16 |
| Curved end | $30–$50 | $40 |
| Linear end | $30–$50 | $40 |
| Round angle | $40–$60 | $50 |
| Sharp angle | $40–$60 | $50 |
| Double-curved end | $50–$70 | $60 |
| Double end | $50–$70 | $60 |
Cost by Glass Block Style
Different glass textures, patterns, and opacities can create very different looks. The more transparent the glass brick, the more light is able to get through, and the less privacy the window will offer.
Acrylic blocks offer similar transparency and security to glass, but they’re substantially more expensive.
The disc-shaped pattern in the center of this type of glass block helps break up visibility without blocking light.
Though completely transparent, clear blocks usually have a slight green tinge due to iron oxide in the glass. Consider additional window treatments for extra privacy.
Colored glass blocks are available in nearly every color, but are typically more expensive than other options.
Interlocking lines on these blocks form a diamond pattern that decreases transparency.
Though frosted blocks obscure the most light, they also offer the most privacy, making them popular for shower enclosures and other bathroom applications.
Ice blocks have a crinkled interior texture that distorts the appearance of items behind them.
These are similar to ice glass blocks, but their interior texture appears more wavelike than crinkled.
Cost by Glass Block Brand
Many top-rated window brands don’t sell glass block windows. You’ll have to specifically look for a glass block manufacturer. We’ve listed some popular manufacturers and their typical cost ranges below.
| Brand | Cost Range | Average Cost |
|---|---|---|
| TAFCO | $6–$10 | $8 |
| Pittsburgh Corning | $6–$20 | $13 |
| Seves | $8–$12 | $10 |
| Mulia | $8–$20 | $14 |
| Quality Glass Block and Window | $8–$20 | $14 |
Labor Cost of Glass Block Installation
Be prepared to pay about $45 per hour for labor, whether you’re replacing an existing window with glass blocks or cutting a new one.
Ease of Assembly
Most prefab glass block windows come preinstalled in a vinyl frame. Otherwise, the installer will need to use mortar or silicone sealant to set the glass blocks in the aluminum, composite, or wood frame. For walls or larger windows, we recommend running rebar between the bricks for extra support, though this increases installation costs.
| Method | Prefab Cost per Square Foot | Custom Cost per Square Foot |
|---|---|---|
| Unframed mortared | $25–$75 | $50–$150 |
| Vinyl framed | $30–$80 | $60–$160 |
| Mortared and rebarred | N/A* | $80–$200 |
Glass Block Opacity
The more opaque the glass block, the more it will cost. For example, completely translucent blocks cost an average of $6–$10, whereas frosted blocks typically cost $10–$20.
Material
Acrylic is a popular glass alternative. Its translucent plastic offers privacy and security just like glass but at a lighter weight. This makes the blocks easier to cut and install. The drawback is an increased price ($12–$25) and decreased durability. Acrylic can scratch and discolor over time and with changing temperatures, so it’s most often used in interior walls rather than true windows.
Prefabricated vs. Custom Glass Blocks
Prefabricated windows take less time to install and thus cost less at $150–$1,000 per window. Custom glass block windows require installers to spread mortar and place dividers between each brick, which takes longer and costs more—about $300–$4,500 per window.
Can You Install a Glass Block Window Yourself?
You may be able to install a prefab glass block window kit yourself if you have experience installing windows or working with grout. We recommend professional installation if you’re installing custom glass block windows.
DIY Glass Block Window Installation
Hardware stores such as Home Depot sell do-it-yourself (DIY) glass block windows installation kits. These kits contain the blocks along with mortar, caulk, spacers, and wall anchors. They’re relatively inexpensive and you won’t have to pay for labor. However, you must ensure that all the glass blocks are secured and the frame is thoroughly sealed to prevent leaks and water damage.
Professional Glass Block Window Installation
If you’re replacing an existing window, a professional contractor can remove the old window and make any necessary window frame repairs. From there, they’ll either slot the prefabricated window into the frame or start mortaring each glass block.
Quick Tip
- Though professional installation adds labor costs to the project, it ensures the job is done quickly and correctly. Speed is an important consideration if your glass block window is part of a bathroom remodel.
How To Hire a Professional Window Installer
Not all window companies install glass block windows, so you may need to shop around to find an experienced installer. Here are some tips.
Check Their Experience
Ensure the contractor has specific experience with glass block windows, particularly if you have a large or custom design in mind.
Ask About Insurance
Make sure anyone who works on your home is bonded and insured.
Read Online Reviews
Check each company’s Better Business Bureau web page and customer review sites such as Truspilot and Google Reviews.
Get Multiple Estimates
Get estimates from at least three local professionals for a better sense of your area’s average costs.
How To Save on Glass Block Window Installation
Glass block windows can be affordable replacement windows if you take the following tips into account.
- Choose clear or textured glass rather than frosted or colored glass.
- Stick to standard-size glass blocks and window frames.
- Opt for prefabricated glass block windows instead of custom ones.
- Schedule your installation during the off-season when labor costs are lower if you’re hiring a pro.
- Go the DIY route and use a kit if you feel knowledgeable enough.
Is Glass Block Window Installation Worth It?
Glass block windows are an excellent choice for bathrooms, garages, and basements. They cost just slightly more than standard windows and offer a distinct look. Although this type of window doesn’t open and thus can’t serve as an egress window in basements, it’s more energy-efficient and secure than a traditional window. Additionally, you can choose your privacy level by comparing glass blocks of various colors, textures, and opacities.
FAQs About Glass Block Window Installation Costs
Do glass block windows increase home value?
Glass block windows don’t directly increase home value, but most homebuyers value natural light and energy efficiency. Since glass block windows have these benefits, they may make your home more desirable.
Are glass block windows waterproof?
Glass block windows are completely sealed with mortar and caulk, with no moving parts to allow potential leaks. Thus, they’re essentially waterproof.
Are glass block windows storm-resistant?
Yes, glass block windows rival top-rated storm windows in terms of storm resistance.
They’re extremely resistant to water and air leaks, and they can hold up to direct impacts without shattering.
How long does it take to install a glass block window?
A small prefabricated glass block window can be installed in 30–90 minutes, though larger windows can take up to six hours.
Our Rating Methodology
We back up our window ratings and recommendations with a detailed rating methodology to objectively score each provider. We conduct research by speaking with company representatives, browsing product selections, analyzing window line specifications, and conducting focus groups and consumer surveys. We then score each provider against our review standards for window variety, value, trustworthiness and transparency, window features, and customer service to arrive at a final score on a 5-point rating scale.
To share feedback or ask a question about this article, send a note to our team at reviews@thisoldhousereviews.com.