Choosing the right glass for your windows is one of the most important home renovation decisions—it ensures safety, energy efficiency, and comfort. If you don’t know where to start, we’ve got you covered with this comprehensive guide about the most common types of window glass. Read on to discover the key features of each!

Key Takeaways

• Clear float glass is the most commonly used window glass, known for its excellent light transmission and versatility in various applications.
• Other common types of window glass include annealed, heat-strengthened, tempered glass, the latter being the strongest, as it shatters into smaller, blunt pieces upon breaking, making it ideal for high-risk environments.
• Laminated glass enhances security and noise insulation by holding the glass pieces together when broken, while Insulated Glass Units and Low-E glass improve energy efficiency and comfort.
• For enhanced privacy, you can install tinted, stained, reflective, and textured glass.

1. Clear Float Glass

Clear float glass is the world’s most common type of window glass. It is made primarily from soda-lime-silica. The raw materials are melted at approximately 2,900 degrees Fahrenheit (1,600 degrees Celsus) in a furnace, and then the molten glass floats in a tin bath at 2,000 degrees Fahrenheit (1,100 degrees Celsius) to achieve the desired form – a flat, smooth glass.

It is then polished with fire, cooled down, and finished with automatic cutters that adjust the glass to the desired length. Usually, the thickness of clear float glass ranges between 0.4 and 25 mm (0.01-1 inches).

This type of glass has excellent light transmission and optical clarity, allowing approximately 87% of light to pass through. Another advantage of this type of window glass is its durability and customizability.

Clear float glass is used to produce other types of window glass, including tempered and Low-E glass.

2. Tempered Glass

Tempered glass, also called toughened glass, is usually installed for safety and durability. Given that it’s manufactured using thermal or chemical treatments that increase its strength, this glass type is up to four times stronger than regular glass.

This strength is achieved through a process of heating the glass at more than 1,100 degrees Fahrenheit (600 degrees Celsius), followed by brief high-pressure cooling, known as quenching, which increases its durability. This is why when tempered glass breaks, it shatters into tiny, blunt pieces rather than sharp shards, reducing the risk of injury.

This type of glass is often required by building codes in areas with an increased risk of collision. It is frequently used for balcony doors, facades, shower doors, and bathrooms. This glass is also used for refrigerator trays, smartphone screen protectors, and cookware.

3. Annealed Glass

Annealed glass is produced through a controlled cooling process that reduces internal stresses, enhancing its durability.

This glass is similar to tempered glass, except that the latter undergoes a heat treatment before the cooling process. Unlike tempered glass, which breaks into small pebble-shaped pieces, annealed glass breaks into long, jagged shards that can lead to injury.

4. Heat-Strengthened Glass

Like tempered glass, heat-strengthened glass is produced by being heated at approximately 1200 degrees Fahrenheit (650 degrees Celsius) and then cooled down to create compression in the glass. The main difference between the two is the rate of cooling. For heat-strengthened glass, the cooling is much slower than for tempered glass, so the compression is lower.

Heat-strengthened glass is twice as strong as annealed glass but weaker than tempered glass. Another difference between these two glass types is that heat-strengthened glass breaks into larger pieces, which remain in the system until removed, while tempered glass breaks into small cubical pieces.

5. Laminated Glass

Laminated glass is a safety glass made of two or more layers of glass. Between these, there are thin interlayers made of polyvinyl butyral or ethylene-vinyl acetate that hold the glass together when it breaks.

In other words, when laminated glass breaks, the pieces don’t just fall off; instead, they stay glued together, looking like a spider web. This feature makes laminated glass an excellent choice for areas prone to forced entry or impact, such as windows in high-security buildings or homes near busy streets. It is also used in regions that experience frequent natural disasters like earthquakes and hurricanes.

Apart from safety, laminated glass has soundproofing abilities and can block up to 99.9% of UV rays.

6. Tinted Glass

Tinted glass is another popular option for both residential and commercial buildings. It incorporates a thin colored film that modifies its visual and heat absorption properties. One of the key advantages of tinted glass is its ability to enhance privacy by limiting outside visibility while still allowing some natural light in.

Furthermore, tinted glass reduces glare and heat gain from direct sunlight, making it an energy-efficient option.

The depth and darkness of tinted glass can be customized to meet aesthetic and functional preferences, offering a stylish solution for controlling light and heat gain.

However, you probably don’t want tinted glass on a window wall, for instance, which is usually installed for views and natural light. Instead, this type of window glass can be ideal for bathrooms, for example, where you need more privacy.

7. Low-E Glass

Low-E (low emissivity) glass is designed to minimize heat transfer, improve energy efficiency, and protect against UV rays. This type of glass has a microscopically thin and transparent coating added in the manufacturing process. It reflects heat but doesn’t affect the window’s Visible Transmittance rating. The result is an energy-efficient window that helps maintain indoor temperatures and reduce energy consumption. Low-E glass also offers significant UV protection, protecting your furniture and fabrics against fading.

A window can have several Low-E coatings, depending on how many glass panes it has. For example, if a window has two glass panes, it has four glass surfaces. You can add Low-E coatings to any of the four surfaces depending on where you live:

• Passive Low-E coatings, used primarily in colder climates, as they keep solar heat in, are added on the 3rd and/or 4th surfaces.
• Solar control Low-E coatings, used in warm climates, as they reflect solar heat, are added to the 2nd surface.

8. Insulated Glass Units (IGUs)

A window glass is an Insulated Glass Unit (IGU) when it has two or more glass panes. In turn, these are separated by spacers. The space between the panes is filled with inert gas, which serves as an insulator.

IGUs are significantly more energy-efficient than single-glazed windows, thus contributing to lower energy bills. They can also help prevent condensation, reduce noise transmission, and improve overall indoor comfort.

With the increasing focus on energy efficiency and sustainability, IGUs have become a popular choice for both new and replacement windows. Most homeowners choose double-glazed windows as they’re more affordable and efficient enough to keep their homes comfortable. However, if you live in cold climates, you can consider installing triple-pane glass windows. Keep in mind that given their weight and complex installation, they’re more expensive.

If you’re looking for a budget-friendly alternative to triple-glazing, you can opt for Magic’s double-glazed windows equipped with our Thermal Blinds, which are made from insulating materials that improve the window’s energy efficiency by 40%. This combination makes our double-pane windows even better than triple-pane windows.

9. Reflective Glass

Reflective glass features a mirror-like coating applied during the float process that limits solar heat gain, making it an excellent choice for sunny climates. From the outside, reflective glass mirrors the outdoors. From the inside, the glass is transparent, allowing for excellent views.

Reflective glass is commonly used in large windows and window walls mainly because it ensures complete privacy during the day and makes them appear more aesthetically pleasing.

On the other hand, reflective glass affects a window’s Visible Transmittance and can make the house feel darker. This can increase the amount of artificial light you’ll use. In addition, reflective glass doesn’t offer privacy at night because it loses its reflective properties when interior lights are on.

10. Textured and Stained Glass

Textured glass is designed to provide privacy while allowing light to pass through. Acid-etched glass, for instance, has a frosted look that obscures visibility while allowing diffused light in. These windows are usually installed in bathrooms, doors, or decorative panels. They can be customized however you want, as there are numerous textures available.

Stained glass is a decorative glass colored by the use of metallic salts. These windows are now considered objets d’art, as one needs both artistic and engineering skills to create intricate designs.

11. Impact-Resistant Glass

Impact-resistant glass, also known as hurricane glass, is designed to withstand severe impacts and provide essential safety during storms. This type of glass consists of laminated and tempered glass, as well as polyvinyl butyral.

Besides protecting your home from severe weather conditions, impact-resistant windows are burglar-proof.

How Does Magic’s Glass Technologies Stand Out in the Industry?

At Magic, we have brought glass production in-home. This means we can fully customize our windows based on the size, shape, and color you want and add products of the highest quality in our Insulated Glass Units, such as the best-performing warm-edge spacers.

In addition, our IGUs have 25%-30% more inert gas between panes because we’ve extended that space from the traditional ½ – ¾ of an inch to 1 inch. Furthermore, given that we can oversee the entire glass production process, we guarantee maximum quality control.

Therefore, regardless of what window glass types you’re looking for, you can rest assured that, at Magic, they’re manufactured according to the highest quality standards.

Book a Free Consultation with Magic to Learn More about Our Technologies!

Whether you’ve already picked the glass type you want or still have to make up your mind, you can book a free consultation with Magic, and we’ll take it from there! One of our project managers will consider the tiniest details to find a solution fully tailored to your preferences and needs.

So, if you want to learn more about our glass production process or other innovative window features, contact us today! You’ll be a step closer to the windows you’ve always dreamed of!

Frequently Asked Questions

What is the best type of window glass?

Tempered glass is usually considered the type of window glass, thanks to its strength and heat resistance.

What type of glass is used for windows?

Clear float glass is the most common type of window glass. It can be further treated to produce other glass types, such as tempered, heat-strengthened, or Low-E glass.

Which is the most energy-efficient window glass?

The most energy-efficient window glass is the Low-E glass incorporated in double-pane or triple-pane windows.

How does laminated glass enhance safety?

Laminated glass significantly enhances safety by holding shattered fragments together. This feature effectively reduces the risk of injury from broken glass.

What is the strongest type of glass?

Tempered glass is the strongest type of glass, being four times stronger than regular glass. When shattered, it breaks into small, blunt pieces, thereby minimizing the risk of injury.

What is the weakest glass?

Annealed glass is the weakest glass. It is half as strong as heat-strengthened glass. Tempered glass is 4-5 stronger than annealed glass.

When should I consider using impact-resistant glass?

You should consider using impact-resistant glass primarily in hurricane-prone areas or regions exposed to severe weather conditions, as it offers crucial safety by protecting against high-impact debris.