How much does it cost to install a glass block window?

Glass block windows have been used for decades to provide an insulating, privacy window or as a wall that lets light in. Glass blocks come in a variety of styles, sizes, and colors and may be available in single blocks or readymade windows.

Most people who install these as windows do so in the basement or bathroom, which are two areas that need security and privacy as well as light. The average glass block bathroom window installation consisting of a readymade, ventilated window professionally installed is around $500.

Pros and cons

Like any material you have installed in your home, glass blocks have their positive and negative attributes. Glass blocks are significantly thicker than standard windows, which means that they do a better job of insulating and helping to block air transfer. This may help make your home feel more comfortable while reducing energy bills.

Some glass blocks are also designed to let in the maximum amount of light while obscuring the view. This can mean an increase in privacy for the room without sacrificing any light.

In addition, the thickness of the glass blocks can make them more secure and less likely to be broken into during a burglary, which is why they are commonly installed in basements.

However, the same thickness can also be a drawback in hot weather. The sun penetrates the thick glass blocks and can quickly heat up a room. And unless you purchase a specially ventilated block window that opens, that heat can become trapped.

Also, standard glass blocks do not allow for any air circulation. This is solved with a vent, but not all styles or companies offer this. Finally, they can be difficult to cut and install for those who are not used to working with them, which can increase costs.

Location

Glass blocks are incredibly versatile and can be used in a variety of locations and spaces around the home. Glass blocks are generally sold in two ways: either in loose blocks of a variety of sizes and shapes that are installed on site to form a custom window or wall or readymade windows that can be installed all at once. Depending on the location, you may wish to use one or the other of these styles:

• Basements: it is common for basement block glass windows to be readymade, either solid or vented. Costs start at $200 per window.
• Bathrooms: there are several places in the bathroom where glass blocks can be utilized. The most common is the bathroom window because it lets light in while offering privacy. Vented bathroom windows start at $300 per piece. It is also common in bathrooms for loose blocks to be used to create half walls beside the toilet to offer some privacy and to create unique, walk-in showers without traditional doors. In these cases, the blocks themselves start at around $15 or $60 per sq.ft. installed. For a 4-foot by 5-foot half wall, the cost would be $1,200. For a shower, expect to pay $2,000 at a minimum.
• Walls: dividing walls made of glass blocks were once the norm to disguise architectural flaws. They also divide large spaces without sacrificing light but still provide privacy. A full dividing wall starts at around $3,000 depending on the type of glass used.
• Bar fronts: glass blocks make a dramatic display when installed in front of a bar. The blocks can be lit from behind with LED cable lights to provide a beautiful glow. These projects typically start at around $2,000 and use loose blocks so that ribbon LED can be installed between the rows.

Material

Traditional glass block windows are made from a mixture of limestone ¹, soda ash, sand, and cullet. This mixture is heated to extreme temperatures, melted, and poured into molds to be shaped. True glass blocks offer the best in insulating properties and the most number of styles and colors. Real glass blocks are sold both loose and in prefabricated window panels. The panels offer the best prices in installation because they are designed to be put into place in one piece.

Acrylic, however, is also a choice for when a lighter-weight block is necessary. These plastic-based blocks do not weigh as much but also do not insulate for heat or sound in the same way. They are primarily used for interior applications and not for windows. Acrylic blocks are normally sold loose, to be installed on the spot.

Style

Regardless of the configuration you install the blocks in, they are available in a range of different styles and patterns. Many companies also offer a range of custom options and colors as well, but five common styles are readily available:

Installation

There are essentially two ways of installing the blocks. The first is in readymade groupings or windows. In this case, the entire window is lifted into the frame and sealed around the edges. A special adhesive is used around the edge to hold the window in place and prevent air leaks.

When using individual blocks, they are installed like a brick and mortar ² style. Each glass block is given a special adhesive put on with a caulk ³ gun where it meets the adjacent blocks. The blocks are pressed into one another, and any caulk ³ is tooled off where it may press out. The process can take anywhere from a few hours to a few days depending on how large the installation is.

In most cases, the blocks are custom ordered with corners, end pieces, and curves to avoid needing to make cuts onsite. For this purpose, the area is generally measured and planned out well in advance before ordering the blocks.

Labor

Labor costs vary depending on the size of the project and the type of blocks used. However, most installers charge an average of around $36 per hour for glass block installation. For small jobs like windows, however, a flat rate may be used of around $100 to $300 per window.

A bathroom window made of standard, wavy glass, preset into a window block would take around 1 to 2 hours to install. For a single window like this, the installation would likely cost $100 to $200, with the window itself costing $300 to $400.

A shower block wall made of individual wavy glass blocks creating a curve to accommodate two sides and reaching up to the ceiling would take 1 to 2 days to complete, for a total of $290 to $580 in installation costs. Adding in materials, this project would cost roughly $2,500.

Maintenance

Glass blocks require very little maintenance. Like any glass surface, keep it clean with a squeegee or with a glass cleaner and lint-free cloth. The adhesive between the blocks is not impacted by typical glass cleaners, so maintaining a glass block wall or window is not difficult.

Glass tiles

Glass tiles are not to be confused with glass blocks. A glass block is a large brick measuring up to 8-inches square and 3-inches thick. A glass tile may range in size from a mosaic to 18-inches square but is usually less than ⅜-inch thick. Glass blocks can make free-standing structures or insulating windows, while glass tiles are made for covering another substrate, such as drywall ⁴. Glass tiles may be used to cover the interior of shower walls or a kitchen backsplash ⁵, but they cannot be used to create a wall or window the way that glass blocks can.

Enhancement and improvement costs

Old window removal

If you are removing a standard window to install a glass block window, there may be a removal fee for the old window of around $50.

Lighting

It is possible to light up your glass block walls by installing an LED ribbon between the various rows of blocks. This can add $50 to $300 to the cost depending on the size of the project.

Vent

Many glass block windows have a vent built into them that can open and close to let air through. This is not necessary but can improve the function of the window. Adding the vent increases the cost by about $50 to $100 per window.

Colored blocks

Glass blocks may be clear or tinted a wide variety of colors. Colored blocks start at around $10 per piece.

Additional considerations and costs

• Glass block windows can be difficult to remove. This may mean demolishing and rebuilding the frame, which can add to the costs.
• Glass blocks cannot be used to create load-bearing walls ⁶ because the glass is not strong enough to support the weight of a structure.
• If you live in a hot area, keep in mind that glass blocks allow heat to build up, particularly if they are not vented.
• Glass blocks are considered environmentally friendly and energy-efficient because they do not allow air transfer and are made from renewable sources.
• Glass block windows and exterior walls can be covered with all-season greenery including tall shrubs or trees.

Remodeling Terms Cheat Sheet

¹ Limestone: A type of sedimentary rock, made up of mostly calcite and aragonite

² Mortar: A mixture of Portland cement or lime or a combination of both, sand, and water used to bind bricks, stones, and concrete masonry units together

³ Caulk: A chemical sealant used to fill in and seal gaps where two materials join, for example, the tub and tile, to create a watertight and airtight seal. The term "caulking" is also used to refer to the process of applying this type of sealant

⁴ Drywall: Type of plasterboard, commonly used to build walls and ceilings, composed of gypsum that is layered between sheets of heavy paper

⁵ Backsplash: The upright surface, often made of tile, behind a kitchen counter, sink, or stove, that protects the wall from damage from splatter due to kitchen activities