People in this country are obsessed with the name Pilkingtons (now a Japense company by the way). Guardian are a top European glass manufacturer and offer some superb coated glass products far in excess of some of the Pilkington's products.

But this is just the maker of the single sheet glass, the quality of your double glazed units in your windows and the U values etc depends on who made them and whether they used Argon in the cavity.

However if you have a low E glass in your roof then be prepared to sweat in the summer. Not only does it not stop solar heat gain it actual promotes temperature rise in your conservatory as it helps to keep the heat locked in.

But to put your mind at rest, the fact that they used Guardian shows that your DGU were made by someone who knows their glass so you shouldnt be overly concerned.

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