Solar control glass | Solar control double glazing for old sash window

What is solar control double glazing?

It is a difficult decision to make which double glazing to install, should you choose gas-filled or vacuum double glazing, and what level of solar control is optimal for your home. Let’s look at what is solar control glass and why it is important for modern and period houses.

Solar control glass is a glass with a layer of special coating. This special coating is designed to reduce the amount of heat that gets through the double glazing. This special layer reflects and absorbs heat.

It also filters light and reduces UV radiation.

Pilkington Spacia™ Cool vacuum double glazing

In this respect, double glazing has the advantage over single glazing. But one condition is essential, especially for your comfort: solar control.

However, many people overlook this important detail. So let’s take a look at what solar control is for double glazing and why you should be concerned about it.

Pilkington product line comparison table

Pilkington product line comparison table

Solar control role during winter

Solar control is the percentage of solar energy that the glass allows through. Classically, this figure is 63%. But depending on the manufacturer and the needs, it will vary.

The higher the solar percentage, the more advantageous it is in winter. Thanks to the sun and east or west-facing windows, you can heat your house for free.

This is ideal for saving on heating costs and making the most of the daylight.

solar glass control during winter time

Solar control during summer

But in summer, the role of solar control for double glazing is quite different.

This time, you will prefer a low percentage so that the heat does not penetrate too much and the coolness is preserved.

However, this is also the role of sash window blinds. So some people will prefer a high percentage so that in winter they have light and in summer they use a blind to protect themselves.

In any case, you can ask the double glazing manufacturer if it is possible to modify or not this percentage which can vary from 20 to 80%.


Solar control is a must in today’s double glazing.

With global warming, the issue of solar control in the UK is becoming more and more important for households.

solar control glass

Contact us if you want to double-glaze your existing sash windows to improve solar control and energy efficiency.

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