Insulating glass has been in further development since 1948. From the old (Thermopane) double glazing to the vacuum glass of today.
We therefore briefly explain what insulating glass is, which types are available on the market, the benefits and the reasons why investing in insulating glass is so essential.

Download the brochure

BENGglas _vacuum glass


Insulating glass includes all types of glass that provide better insulation than single glazing. As a rule, insulating glass consists of several layers of glass with air, gas or a vacuum in between. Although insulating glass often consists of two layers of glass, there are also variants with three layers of glass, known as triple glass.


BENGglas renovation


Glass covers a large part of the entire building envelope. Poorly insulating glass is therefore often found to be one of the weakest links. Which can lead to high energy costs and poor living comfort. By choosing insulating glass with the best insulation value, a major step forward can be made in the energy label or the BENG standard can be made more conclusive sooner.


Insulating glass is divided into three categories:

  • Double glazing: standard double glazing (Thermopane)
  • High-efficiency insulating glass: HR, HR+, HR++ and HR+++ (Triple) glass
  • Vacuum glass ( BENGglas )

Below we briefly explain the differences.


Double glazing became the first step after single glazing and is also one of the most common types of insulating glass in older buildings. Popularly, the old double glazing is also called Thermopane, named after the brand that was the first to market the type of insulating glass.

The glass consists of two panes of approximately 4 to 5 mm thick with a cavity filled with air in between. Air conducts heat better than a gas filling or a vacuum, which means that the insulation value is less good than with other types of insulating glass.

HR++_HR+++ double glazing HR


High-efficiency insulating glass became the next step in insulating glass after standard double glazing. By replacing an air filling with a gas filling, the conduction from inside to outside was reduced. This resulted in an immediate improvement in the insulation value.

By applying heat coatings to the window, another step in insulation performance was achieved (HR+, HR++). These reflect the heat back into the home. By expanding the entire package with a third pane, the insulation performance was improved again, also known as HR+++ or triple glazing.



HR++/+++ glass insulates considerably better than standard double glazing, but quickly becomes very thick and heavy. Because these types of insulating glass do not fit into the existing window frames and hinges and locks, it is often essential to replace both, which can lead to high costs.

In addition, the insulation value cannot compete with that of vacuum glass (U=0.40) and slowly increases over the years due to cracks in the frame. not the case with vacuum glass The lifespan of HR++/+++ glass is also shorter than vacuum glass (20-40 years versus 25-50 years).


BENGglas is the latest step in the development of insulating glass. By not using air or gas between the two panes, but instead creating a vacuum, conduction is kept to a minimum. This allows much better heat insulation, but also much better sound insulation, to be achieved with less material.

+ comfortable and quiet living
+ the preservation of the existing window frames and hinges and locks (ultra-thin)
+ a longer lifespan
+ 15% natural light compared to triple glazing


Spacers are small dots found between the two glass plates. These are intended to distribute the pressure on the glass during the vacuum process. Without spacers the glass would break. BENGglas has a very low number of spacers compared to other brands. This means you can enjoy the best results BENGglas

These are intended to extract moisture between the glass for a long time.
This way the vacuum is kept intact. Depending on the production process, you will be dealing with an absorption point or absorption strip. At BENGglas we work with slim absorption strips as standard, with the exception of BENGglas +. These strips fit neatly behind the window slats.

Vacuum caps were used to extract the air between the two windows. However, technology is continuously developing. This now also makes it possible to extract air from the edges. Vacuum caps are therefore no longer necessary. BENGglas therefore offers a wide range without vacuum caps. This way you always enjoy an optically beautiful result.


Schott glas_Restover_Pulled monumental glass


Additional functions can be assigned to (vacuum) insulating glass by applying additional finishing processes such as coatings, foils, extra panes or by applying unique product techniques.

This includes burglar-resistant, fall-proof, fire-resistant, sound-insulating, monumental and sun-resistant glass. Such post-processing is also possible with BENGglas .

Inquire about the options by emailing or consulting a dealer near you!


To make an old home or building with old double glazing more sustainable, the choice quickly falls on HR++, Triple or vacuum glazing. However, by choosing vacuum glass you immediately save on the purchase of new window frames and on new (heavier/more expensive) hinges and locks. You immediately start with long-term savings in your energy bill of 25 to even 50 years. Where the insulation value of high-efficiency glass increases slowly due to leakage and has a shorter lifespan of between 20 and 40 years.

Standard double glazing
HR glass
HR++ glass
Triple glass
Insulation value
Air + coating
Gas + coating
Gas + coating


vacuum glass is more expensive to purchase than HR++/+++ glass, but the value of the glass goes directly into improving your energy label and saving materials. That is why it is not smart to only look at the base price, but to take into account potential increases in value and savings. Therefore, always request a no-obligation cost comparison from one of the BENGglas dealers to make a well-considered choice.


What is the history of glass?

Glass was invented accidentally by heating glass grains in sand to create glass beads. These pearls were originally worked for beads, but later crafted into larger shapes from 1,500 BC. The Romans invented the casting process around the first century AD and made it possible to produce the first "flat glass". The glass was not really transparent. And due to the lack of lime, these windows were still very vulnerable.

Around the Middle Ages (approximately 1,000 AD), production techniques were significantly improved and it became possible to produce clear glass using coal and advanced furnaces.
As a result, quality increased and the existence of the first large glass concerns began.

In the following centuries, the techniques and compositions of glass were greatly improved and the possibilities with glass are now endless.

What types of insulating glass are there?

There are different types of insulating glass available, each with its own properties and applications. Some of the most common types of insulating glass are:

  1. Double glazing or Thermopane: This is the most common type of insulating glass and consists of two glass panels with an air space (cavity) between them. The air space may be filled with air or an insulating gas such as argon or krypton. It is commonly used in homes and commercial buildings. Air conducts better than noble gas, which does not improve insulation performance. Small cracks can develop in the edge seal, causing the insulation performance to decrease over the years.
  2. High-efficiency glass: HR++ and HR+++ (also called triple glass) is double glazing with a coating and insulating glass between the glass plates. This achieves better insulation. HR+++ (also called triple glass) achieves better insulation performance than HR++ because the construction consists of three glass plates. Small cracks can develop in the edge seal of both types, causing the insulation performance to decrease over the years.
  3. Vacuum glass : This type of glass consists of two thin layers of glass that are hermetically sealed so that virtually no heat loss can occur. In a vacuum, virtually no (heat) conduction can take place. What is heated indoors retains its heat. The heat from outside also stays outside. It offers the best thermal insulation of all types of insulating glass and retains its insulation value compared to traditional insulating glass due to the advanced edge seal.

The choice of the right type of insulating glass depends on the specific needs. Additional functions can also be assigned to the glass with additional films or coatings. Consider functions such as: sun-resistant, fire-resistant, burglar-resistant or, for example, extra sound insulation. Such applications are possible with BENGglas . Complete the contact form to request the options.

How long does insulating glass last?

Traditional insulating glass (HR++, HR or triple glass) has a lifespan of approximately 15 to 30 years, but gradually loses its insulation value due to cracks in the sealing edge. For comparison: the expected lifespan of BENGglas is between 25 -50 years (or even longer), while retaining its insulation value.

It is important to note that the lifespan of insulating glass can vary depending on conditions and maintenance.
Regular maintenance and careful installation can extend the life of all types of insulating glass. BENGglas has a warranty period of 15 years BENGglas Traditional insulating glass has a warranty period of 10 years.

Advantages and disadvantages of insulating glass

HR++/+++ glass offers significantly better insulation compared to standard double glazing. However, it quickly becomes thick and heavy, making it unsuitable for existing window frames and hinges and locks. It is often necessary to replace both the glass and the window frames, which can lead to significant costs.

In addition, the insulation value cannot compete with vacuum glass (U=0.40), and over time this value slowly increases with HR++/+++ glass due to cracks in the frame. This problem does not occur with vacuum glass. In addition, the lifespan of HR++/+++ glass is shorter than that of vacuum glass (20-40 years compared to 25-50 years).

Price of insulating glass

vacuum glass is more expensive to purchase than HR++ or triple glass, but the value of the glass goes directly into improving your energy label and saving materials. That is why it is not smart to only look at the base price, but to take into account potential increases in value and savings. Therefore, always request a no-obligation cost comparison from one of the BENGglas dealers to make a well-considered choice.



Do you have a question? We are happy to support you. Send us a message via the contact form and we will get back to you within 24 hours.

This field is for validation purposes and should not be changed.