Glass Block Window Installation

What Are Glass Block Windows?

Glass block windows might seem reminiscent of the ‘80s, but this style of windows serves many purposes and is still seen in homes around the country. 

Made up of individual blocks of obscured glass, they can be created in a huge variety of shapes or sizes. Glass block windows offer privacy and fortitude without sacrificing light, which makes them a unique type of window for a variety of needs. 

How Are Glass Block Windows Installed?

Glass block windows are installed the way you might install bricks; using mortar and layering the blocks one row at a time. As the mortar cures over the next 48 hours, the blocks will need to be reinforced with anchors and kept level throughout the process. As the mortar dries, residue should be removed from the blocks themselves. Finally, after the mortar sets, the entire block wall will have to be sealed to prevent moisture leaks.

Most Popular Places for Glass Block Windows

Typically, glass block windows are seen in basements. These windows allow light to filter into dark basements but are made with frosted or textured glass which obscures the view into your home. They’re also stronger than typical single hung windows and the like because they offer thicker layers of glass and are made using masonry techniques. Using these windows on the ground level of the home, leading into the basement is especially helpful because they prevent moisture from seeping in.

Another common spot for glass block windows is the bathroom. For the same reason they’re used in basements, glass block windows in bathrooms protect your privacy and prevent moisture from seeping into the home or out, in a room where water is prevalent. 

Of course there are tons of other uses for glass block windows in your home, including as decorative barriers. For example, some homeowners use them as shower walls or add them beside interior doors in rooms that don’t get much light. 

Glass Block Window Replacement Costs

Glass Block Window

Average Installation Cost $400 - $1100

Cost Breakdown

• Materials 65.1%
• Labor 34.9%

Pre-built glass block windows range in price from $18 per square of glass block or $25 for frosted privacy window squares. You might pay more to have your installer custom build your windows. 

The average cost for a glass block windows installation is $400 to $1,100 per window, but your exact cost will vary based on a handful of factors including the following.  

Sizes of Blocks

Glass blocks come in 4-, 6-, and 8-inch varieties, though you can also order custom-sized blocks. 6-inch blocks are the most popular type. 4-inch blocks are used mainly as a design accent and 8-inch blocks are best-suited for larger windows or in areas where you need a lot of natural lot. Generally, the larger or more customized a glass block is, the more expensive it gets.

Number of Blocks

A typical glass block window installation uses 15-20 blocks.

However, the smallest glass block windows may use as few as 12 blocks while a large window may use as many as 50 blocks. As a good rule of thumb, plan to use 12-20 blocks for smaller windows and 30-50 blocks for larger windows. 

Energy Efficiency

Glass block windows tend to be quite energy-efficient since they create a tight seal. However, you can make them even more efficient by adding options like a low-e coating or having additional insulation like an argon gas fill added to each block. The more options you add, the more expensive the project gets. However, you may see a return in the form of lower utility bills, which can make the higher up-front cost worth it.

Local Installation and Labor Costs

On average, you can expect labor rates for a glass block window to fall between $50 and $100 dollars per hour and for a standard-sized window to take anywhere from four to eight hours to install. A larger window or a window with a complex design involving several block sizes can take longer.

Demolition, Materials, and Other Costs to Consider

Do you have an existing window where your glass block window will go? Or are you creating a brand new opening? Demolition costs, the costs to prep the space where the new window will go, and the cost of materials needed to create a space for the window or to finish out an existing opening also need to be factored into your project. 

Since these costs ultimately depend on the materials your home is built from as well as if an opening is already prepped for the glass block window, this cost will vary widely from one home to another. It may cost as little as a few hundred dollars to as much as a few thousand.

What Else to Know

As you might expect from the above, the cost of replacement windows will vary by average prices in your region and based on your specific home’s needs. Speak to a reliable glass block window installer near you today to see how much your project might cost.

For an estimate of your own project costs, you can try using our window replacement calculator, which offers insight based on the scope of your particular project. 

One last note: manufactured glass block windows are often more air tight than those built by local installers. Ask any contractors you decide to get a quote how their windows get built. 

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Glass Block Window Types

How much light and privacy you need your window to provide as well as where your window will ultimately go both impact what type of glass block window you need.

Privacy Bathroom Glass Block Windows

For areas like the bathroom where you are prioritizing privacy, choose a frosted, patterned, or colored glass block. You can even customize the design you want, like adding stripes or a rainfall pattern, so that your window matches your aesthetic.

Basement

In addition to choosing energy-efficient features, different sizes to maximize light, or different patterns to provide privacy, you can also get fire-rated glass blocks. If your furnace (or other heating element) is installed in your basement or if you use your basement as additional living space, then this additional safety feature is an important consideration. These types of blocks can withstand very high temperatures and can slow the spread of fire.

Glass Block Windows With Vents

Because glass block windows are built using mortar, these windows are fixed and cannot be opened and closed like other types of windows. To allow for air flow, some of these windows and block walls can be built with small vents that open and close and are set within the wall of glass blocks. You can even add a hopper window [LINK] to a glass black window to allow for maximum ventilation.

Air flow is especially important in both bathrooms and basements where moisture and/or humidity may be a concern.

Pre-Built Glass Block Windows

Glass blocks can be purchased and built into a wall of your own custom design, or you can purchase pre-built glass block windows in various sizes. These windows come fully sealed and ready to install in your home. Because they are pre-fabricated to fit standard window size openings, they are also easier to install, which may cut down on labor costs.

One note: if you want a specific design or have an unusually-sized opening, then pre-built is likely not going to be a feasible option for you.

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Glass Block Window Styles

There are tons of varieties of glass block windows including window blocks in various shapes and sizes. 

• Shapes. While less common, these blocks are made in rectangular as well as round shapes. 
• Finishes. You can also opt for different finishes, each of which obscures the view through the glass to keep your privacy intact. Glass windows come frosted or with various textures and designs including waves, diamond and ribbed designs. 
• Colors. Some manufacturers sell colored glass as well, offering the same privacy features while allowing light to filter through and change colors. 
• Thickness. Finally, glass blocks typically come in thicknesses of 3 or 4 inches, offering maximum durability compared to other types of glass windows. 

Benefits of Installing Glass Block Windows

There are several benefits to installing glass windows. 

1. Light and space. These windows can be designed to maximize light in any room and to fit on any wall, making them a great choice for narrow wall spaces or other unusually-sized areas.
2. Privacy. Their unique design makes it impossible to see through into a home, but they still allow light to filter into the room. Like frosted windows, glass blocks achieve this with texture and patterns in the glass. 
3. Security. These windows are considered more secure as they are made with thicker layers of glass than typical windows, making them harder to break. That means they’ll last longer overall while helping to  prevent break-ins to your home.
4. Moisture protection. They are made with masonry techniques and then sealed to prevent moisture from getting in, making them a good waterproof window solution. 
5. Cost. Glass block windows are often cheaper than other types of windows.

Before Buying Glass Block Windows: Factors to Consider

There are a few things to think through to help you decide if this is the best type of window for you.

• Sealing. It is recommended that you reseal the windows at least once every five years to maintain their airtightness. Doing so will not only prevent moisture from seeping into your home, it will also help maintain your home’s temperature by trapping hot or cold air inside, depending on the season.
• Energy efficiency. Because they are both durable and air tight, glass block windows are considered energy efficient. If you decide to choose a glass block window with ventilation, the energy-efficiency of the window will decrease.
• Window location. These windows are best for rooms that require privacy but that you would still like lots of light in. If privacy is not a concern for you, other window types may be better-suited for your project.
• Your climate. How hot or cold your area gets may mean you need special glass or additional insulation for your blocks in order to keep your home at a comfortable temperature. This will add to your final project costs. In general, if your area experiences extreme temperatures in either the summer or winter (or both), plan to invest in both low-e glass as well as an argon gas fill.
• Cleaning and maintenance. Like all windows, you’ll want to clean your glass block windows with a glass cleaner on a regular basis,  and keep an eye out for chips and cracks that could compromise their features.
• Lifespan. Installed properly and maintained regularly, glass block windows can last for 15 to 30 years. 

Finding Glass Block Window Installers

Building and installing glass block windows is a job for the pros. Find a local installer in your area by searching for general window installers or by using our resources. 

These pros will be able to recommend the best types of windows for your particular project. Make sure the installer you choose has done this type of window work before to help ensure safe and proper installation of the final product. 

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