Commonly asked questions about Planitherm

We’re here to help

If you have questions about Planitherm glass and how it can help maximise comfort in your home, start by checking these common questions and answers - the solution may be there. If you still need some help, please contact us or speak to an installer.

Why should I have Planitherm Comfort glazing installed in my windows?

When it comes to replacing your windows, the glass really does make a difference.
Glass will typically make up 70% of your window and is at the heart of controlling the flow of natural light, the level of safety and security, of heat retention and even the level of furniture fade protection.
Choosing the right glass for your home will have a huge impact on the performance of your windows, so it’s important to get it right.
Government Building Regulations require us to use energy efficient products that help to reduce CO2 emissions and protect the environment. Planitherm is the UK’s leading energy efficient glass and our full range can be incorporated into any style of window frame. Using Planitherm Comfort glazing is an easy and efficient way of complying with these regulations whilst offering a number of other benefits. Click here to find out more


Are the coatings and laminated layers on the glass permanent?

Yes. The coating is permanent, invisible and hermetically sealed within the glass unit so will last the lifetime of the window. For product options that include a laminated layer, the layer is permanently adhered between two panes of glass.

Will the coatings and laminated layers affect the appearance of my windows?

No, the appearance remains neutral. The coating is completely transparent and microscopically thin, so it is not visible to the naked eye. Laminated layers are also very thin and totally clear.

Can I specify Planitherm glass with any type of window frame?

Yes, all Planitherm Comfort glazing options can be included in any size of double glazed window unit and used with all popular frame materials and types, including UPVC, wood and aluminium. Members of the Planitherm Network are installers who can provide you with comprehensive advice and installation expertise. 

Can Planitherm glass be used in single glazing?

Due to the nature of the Planitherm coating, the coated side must always be enclosed in a sealed unit. As such, the Planitherm range is not available in single glazing.

Where should the Planitherm pane be positioned in my double glazing?

The Planitherm coating is generally positioned on face 3 of a double glazed unit, though it is possible to place the coating on face 2 without affecting the U-value. The coating must always face the cavity to protect it from the external atmosphere.

If Planitherm lets the sun in, does it let anything out?

The glass has a microscopic, transparent metallic coating that allows heat from the sun to pass through the glass to warm the room, and reduces the amount of heat which escapes through the windows. This means it takes less energy to maintain a warm, comfortable home.

Will Planitherm make my house too warm in summer?

Planitherm has been designed to provide homeowners with warmer more comfortable homes and improve energy efficiency. It has excellent thermal insulation whilst maximising the amount of warmth absorbed from natural daylight, saving you money on your heating bills. The actual amount of natural solar heating allowed through your windows will vary depending on their orientation, size and the geographical location of your home. The Comfort Plus package is designed to reduce overheating, which is particularly useful for large glazed areas such as bi-fold or patio doors, and for South and West facing rooms with sunny aspects.

Can I increase the level of noise reduction my Planitherm windows provide?

Potentially. Every installation is different, so please discuss what's possible with your preferred installer.

I have condensation on the outside of my windows, are they faulty?

Condensation on the outer pane is a common occurrence, particularly at certain times of the year.  Energy efficient windows (such as those including Planitherm glass) help to capture heat from outside and reflect the heat back into the room.  Therefore it is an unavoidable consequence that the outer pane of glass is cooler than it would have previously been with less efficient or older-style double glazing.  You will now note that your windows with Planitherm have helped to eliminate any condensation you had on the inner pane, due to your inner pane now being warmer than it may have been with your older windows.

I have double glazing; does this mean my windows are energy efficient?

Of course older-style double glazing offers a limited level of heat retention. However, Building Regulations now state that replacement windows must be energy efficient. The Planitherm Comfort Glazing options are over 50% more energy efficient than older-style, non-coated double glazing.

What does this performance mean to me in real terms?

By switching from older-style, non-coated double glazing to one of the new Planitherm Comfort glazing options, you can benefit from; over 50% improved energy efficiency, enhanced security, up to a 20% reduction in noise, furniture fade protection and a reduction in overheating for large glazed areas, with the Comfort Plus option blocking out 50% of external heat from the sun.

What is a Window Energy Rating?

A Window Energy Rating (WER) is a system for demonstrating the energy efficiency of a window, ranging from A++ to E. A window’s rating is determined by the amount of heat loss, solar heat gain and air leakage of the assembly.
It’s important to remember that Window Energy Ratings are just one element of buying new windows and that our modern glazing options can contribute so much to the comfort of your home. Whether you’re looking for warmth, enhanced security, noise reduction, furniture fade protection, or to enjoy a sun-filled room without overheating, you can find the perfect glass option for you within the Planitherm range.

How do I know my installer has fitted Saint-Gobain glass?

Unfortunately we are unable to brand or watermark the glass with Saint-Gobain or Planitherm due to the large sheet format of manufacture. To gain reassurance that the glass you have been supplied is Planitherm, ask your installer for a copy invoice or delivery note from their supplier clearly stating the Planitherm brand name. You can then use this information to follow the supply chain back to Saint-Gobain Building Glass

I can't find my installer on your list of installers

The installers listed on the Planitherm Network have joined a voluntary scheme requiring installers to self-register. If your installer is not on the installer search they may still be installing Planitherm. Ask them to supply a copy invoice or delivery note from their supplier that states the glass supplied is from Saint-Gobain Building Glass. You can then use this information to follow the supply chain back to the manufacturer.

Is the performance of Planitherm glass proven?

Yes, the performance of Planitherm meets the requirements of European standard BS EN 1096-4 and carries the relevant CE Marking. For more information, visit www.saint-gobain-glass.com/ce

Where can I buy Planitherm glass?

Planitherm glass, and each of the Comfort glazing options, is available to buy via window companies across the UK. Look for members of the Planitherm Network – installers who can provide you with comprehensive advice and installation expertise.

Does Saint-Gobain Building Glass guarantee the quality of work of installer members of the Planitherm Network?

No, installers who use Planitherm can register on the Planitherm Network and have met our Network membership requirements. However, we do not guarantee their work and any queries or issues with your windows should be directed to your installer.

Not found the answer to your enquiry, then contact us?

Please fill out our enquiry form and we will aim to respond within two working days.

Find an Installer

Planitherm glass is available though our approved network of certified installers - we don't sell or install it ourselves.

To find your nearest installers, or search for a specific one, use the search tool below.

Join the Planitherm Network

Are you an Installer or Fabricator?.
Join the Planitherm Member Network.
We'll provide marketing support to help grow your sales:

  • FREE member profile on this site
  • FREE marketing toolkits
  • Co-branded materials
Planitherm Network