Concepts

The U-value indicates how well glass insulates. Simply put: the lower the U-value, the better the glass retains heat in the winter – and keeps it out in the summer. This way, you save on your energy bill and increase your living comfort.
The U-value is influenced by various factors, such as:

• The coating on the glass
• The filling between the glass layers (e.g., air, gas, or vacuum)
• The cavity width – thus the space between the glass layers

How does BENGglas score compared to other types of glass?
Here is an overview of the average U-values per type of glass:

• Single glazing: 5.8 (insulation? Hardly.)
• Double glazing: 1.10
• Triple glazing: 0.70
• Other vacuum glass types: between 0.45 and 0.70
• BENGglas: from 0.35 to 0.50

In short: BENGglas has by far the best insulation value of all.
This way, you save extra on your energy bill!

*U-values measured according to the standards EN 674:2011 and ISO 19916-1:2018 by ift Rosenheim (2025).

BENGglas has an exceptionally low U-value starting from 0.35 W/m²K, which means that the glass insulates extremely well. For comparison: this is twice as good as triple glazing (approximately 0.70 W/m²K) and three times better than standard double glazing (around 1.10 W/m²K). Thanks to this excellent insulation value, BENGglas significantly saves on energy costs and helps make your home more comfortable and sustainable. Moreover, this U-value is supported by reliable European testing institutes such as ift Rosenheim and TÜV Rheinland, with recent reports from 2025 that you can consult in our knowledge base. This way, you can be sure that you are choosing quality and maximum energy savings.

When it comes to heat loss through your windows, it's not just about the glass itself. The transition from the glass to the frame also plays a significant role. And that is exactly what the PSI value is about.

The PSI value indicates the heat loss per meter of edge of the window – precisely where the glass meets the frame. The lower that value, the less heat is lost along the edges of your window.
The PSI value is measured at a temperature difference of 1 °C between inside and outside, per linear meter. In other words: how well does your window keep the cold out, even at the edges?
A low PSI value = less heat loss = lower energy costs.

What does this mean in practice?
The insulation value of the glass is important, but the frame and that edge zone (the transition) count just as much. Here you can see what to expect with BENGglas in different combinations:

• Aluminum frame + BENGglas Hybrid
  PSI value: 0.035 – 0.04
• Wooden frame + BENGglas
  PSI value: 0.05 – 0.09
• Aluminum frame + standard BENGglas
  PSI value: 0.09

The sound insulation is expressed in a so-called Rw (C; Ctr) value. What does that mean exactly?

• Rw is the standard sound reduction value in decibels (dB).
• C is a correction for sound with many high tones, such as playing children or fast road traffic.
• Ctr is a correction for sound with many low tones, such as humming city traffic or a nearby club.

The higher the Rw value, the better the glass blocks sound. But if you are greatly affected by low tones (such as traffic or loud bass), then the Rw + Ctr value says the most about the actual insulation.

An example:

A value of Rw (C; Ctr) = 30 (-1; -4) means that the glass reduces sound by an average of 30 dB, but in practice:

• 29 dB for higher tones (Rw + C)
• 26 dB for low tones (Rw + Ctr)

What are the scores per glass type?

• HR++: 31 dB (-1; -4)
• HR+++: 33 dB (-2; -6)
• BENGglas: 36 dB (-2; -3)

And you can see that reflected in practice:

• HR++ glass reduces sound between 30 and 37 dB, depending on pitch.
• HR+++ ranges between 31 and 27 dB – less effective with low tones.
• BENGglas remains stable with 34 to 33 dB — thus strong performance at all pitches.

In short:
With BENGglas, you choose not only top insulation against cold, but also peace in the house. 

The LTA value (light admission factor) indicates how much natural daylight enters through the glass. The higher the value, the more light enters your home — and you notice that immediately. Daylight not only makes your home more pleasant to live in but also helps save energy. The more light that comes in, the less often you need to turn on the lights.

More or less light? You choose

Not every room needs the same amount of light. In a home or building with a lot of glass or direct sunlight, a lower LTA value can be beneficial. This way, you prevent bright glare, overheating, or discoloration of furniture and floors. That's why BENGglas offers different glass variants — from clear to more sun-blocking — with high and lower LTA values, depending on the function of the room and the orientation of your facades. Whatever you choose: your insulation is always top-notch, with a U-value up to 0.35.

Want to know what best suits your plans? We are happy to think along with you.

The G-value (solar heat gain coefficient) indicates how much solar heat enters through the glass. So: how much free heat from the sun do you actually feel inside?
Good to know: no matter which G-value you choose, with BENGglas you are always assured of excellent insulation – much better than HR++ or triple glazing.
And you'll notice: your house loses less heat, stays at temperature longer, and you need to heat less. Especially in winter or in older homes, this significantly reduces your energy bill.

What does differ: how much solar heat and daylight you let in.

• Higher G-value → more solar heat inside. Great for bright spaces or cold facades.
• Lower G-value → more solar heat blocked. Ideal for lots of glass, warm rooms, or summer sun.

You choose what suits you
BENGglas is available in various versions, each with its own balance between light, heat, and sun protection.

Do you want extra daylight? Block more sun? Or a bit of both? You decide what is important — and whatever you choose:

• it fits perfectly in your existing frames
• it is slim, light, and super insulating
• it contributes to a more comfortable indoor climate

Are you unsure what works best in your situation? We are happy to think along with you.

If you have ever looked closely at vacuum glass, you might see them: small dots between the two glass panes. We call them spacers.

Spacers are tiny supports in the vacuum cavity (the space between the glass panes). They ensure that the glass layers are not drawn towards each other when the air between them is removed. Without these supports, the glass could literally break due to the pressure.
At BENGglas, the spacers are:

• Placed only every 55 mm – which is much less than other brands of vacuum glass.
• Anthracite in color, making them much less noticeable than clear or silver-colored variants that reflect light.

Advantage for you?
A beautiful, calm, and unobstructed view through your windows, without disturbing reflections or a 'grid'-like effect that you sometimes see with other types of vacuum glass.

Note: during the condensation season, you may notice a kind of 'dam' pattern on the glass. This means that condensation forms everywhere on the pane, except around the spacers. This is because these small supports conduct heat slightly better, causing moisture on the outside to set less quickly.
Fortunately, there are special anti-condensation coatings available that can help reduce this effect, so your windows continue to look beautiful for longer — even in humid conditions.

Safety glass means that when the glass breaks, it does not shatter into large, sharp pieces, but into small, blunt granules. This significantly reduces the risk of injuries — extra nice for the safety in your home or building.

• Tempered glass (safety glass): breaks into small, round granules that are not sharp.
• Untempered glass: breaks into large, sharp shards that can be dangerous.

At BENGglas, we consider safety very important. That is why our entire range is standard tempered and therefore safety glass.

Tempered glass is five times stronger than regular, untempered glass. How is that possible? The glass is first heated to a high temperature and then rapidly cooled. This process makes it much more resistant to impact and large temperature differences (thermal breakage is completely eliminated).

And if the glass does break, it shatters into small, blunt pieces (injury-safe) instead of dangerous sharp shards. Extra safe, especially if you have children or pets.

With many brands of vacuum glass, tempered glass is not (always) possible. But with BENGglas, it is! This way, you always get strong and safe glass from us, even if you choose a thin variant.

Laminated BENGglas offers enormous possibilities: you can choose from three types of films (EVA, PVB, or SentryGlas Plus) and an almost unlimited range of counterpanes.

All types of films ensure that no shards come loose in case of breakage. But it doesn't stop there – you benefit from many more smart advantages. Each type of film has unique properties, giving the pane – in addition to the superior insulation value of BENGglas – many extras, such as:

• fall-through safety – safe at height, for all building functions
• burglary resistance – not easy to get through
• extra sound insulation – from -36 dB to -39 dB or even more, noticeably quieter
• better UV protection – your furniture stays beautiful longer
• colors and patterned glass types – your pane completely changes appearance

You can completely decide how to compose your layered pane. Think of patterned glass for a unique appearance, or extra films for maximum safety. Let us know what you are looking for – we are happy to think along with you.