Energy Efficient Glazing

Energy Efficiency, Buyers Guides, Glazing Advice, Technology

Energy Efficiency In Doors And Windows

When it comes to glass doors and windows energy efficiency is exceptionally important.

Naturally, glass doesn’t provide great insulation, however double and triple glazed units can improve it massively.

Over the years technology has improved greatly and modern windows can not only keep your home really warm, but they look really good too.


What are the key features, which will improve your windows performance?

  • Low- E coating – metal oxide coating, applied on the internal part of the glass panel. Allows light and heat to go in and prevents it from escaping.
  • Cavity pocket- gap (which is usually 16 mm thick) between two or three sheets of glass, filled with either air, argon, krypton or xenon. Air does not work as a good insulator compared to other gases.
  • ‘Warm Edge’ spacer- synthetic pane spacer, keeps glass sheets apart from each other, helps to minimise energy loss and reduces condensation.
  • Right frame- all frame materials are available in various different energy ratings. Make sure that you check that too.

Making The Right Choice

How will you know that you have made the right choice?

Ask your double glazing systems supplier what is the U- value (calculation of its ability to transfer the heat) of them.
The lower number they give you the better it is for you.

According to British Building regulations, U- values of newly installed doors and windows should not be higher than 2.0. Larger glass panels achieve better U- values than smaller one.

Passiv Haus Systems can take you down to even 0.69; they are usually triple glazed as a standard.

The goal is to make your house as economic and environmentally friendly as possible.

They have got the best performance when it comes to wind resistance, water tightness, sound insulation and security.

Design matches a timber finish on the inside and aluminium on the outside giving them a Scandinavian look and incredible durability.

Manufacturers usually give a 10-year guarantee for these systems.


High-quality systems will be very effective in preventing condensation.

Condensation happens when humid air meets a cold surface, which is why it is so common on glass doors and windows. Obviously; properly isolated units are much better at preventing it, however, they can not prevent it 100%.

Some glazing suppliers can offer anti-condensation coatings. This is applied to the external surface of the glass and chemically bonded to it. That makes it extremely smooth, so it is very difficult for condensation to stick to it.

Energy-efficient glazing will not only keep your home warm and reduce the cost of your bills, but it will also work as a very good acoustic barrier.

In order to achieve the most efficient acoustic barrier, you should choose the most robust windows. As the thicker the glass is and the deeper your cavity pocket is, the better soundproofing it will provide.

Life Span of Your Doors and Windows

Predicted lifetime for most of the double glazed units is 20 years. However, this period can vary from 10 to 35 years. It all depends on the environment and the way you are going to treat your glass doors and windows.

It’s easier to notice the drop-down in the performance in colder countries (like Scandinavian countries for example).

Performance of double glazed unit will be less satisfying if the seal becomes compromised and gas from between the panels starts leaking, which will reduce its insulating features.

Solar Coatings

Thinking of energy-efficient glazing we usually focus on its ability to retain the heat, forgetting that it is equally important for us to keep our houses at a comfortable temperature during the summer too.

Applying a Solar Control Coating to the glass will prevent your home from overheating and your surfaces from getting discoloured.

That will automatically reduce air conditioning costs, especially in places with large expanses of glass.

It is a metal oxide coating which is spread over the internal face of the external glass sheet of an insulated glass unit.

This coating is available at various different levels of intensity. The most common one is 70/35. That will allow your unit to transmit 70% of light, reducing the G factor (solar heat gain) to 35% at the same time.

Applying solar control coating on the glass does not change its appearance.

Choosing new glazing systems for your house wisely can greatly improve your comfort and be pleasing for your pocket to boot.

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