Robert Winstanley & Co Ltd
Unit 1. 13 Ross Way, Shorncliffe Industrial Estate, Folkestone, Kent. CT20 3UL Tel 01303 249048
Fax 01303 244443

We can usually tell when the central heating goes off on a cold winters day. The radiators might have been on all morning but within an hour, we'll be reaching for our sweaters. Why? Where did all the heat go?

It simply passes through the fabric of your home, your walls, roof and floor, and of course your windows and doors. How quickly your home cools down depends on how well insulated it is, this is measured in 'U' Values. Basically, the more your walls, roof or windows resist the outflow of heat, the lower the 'U' Value and the better it is for your home.

Single glazed windows have a 'U' Value of approximately 5.6W/m²K, whilst ordinary double glazing has a 'U' Value of about 3.0W/m²K.

Windows and doors fitted with specially coated glass reach a ‘U’ Value of  2.0W/m² K or below, which means that they keep the heat in for longer and reduce long term fuel bills.

Because the glass is coated you will sometimes see a slight haze when viewing the glass in certain conditions or see a slight tint which may make certain materials appear differently. Under certain weather conditions you may also get condensation forming on the outside of the glass, this is actually positive proof that the glass is preventing heat loss as the glass is becoming colder than normal and allowing dew to form. It may also be possible that specially coated glass may exhibit minor blemishes and that the tint may also change if windows are made at different times or from different batches, these are not detrimental to the functioning of the glass and are not deemed to be a defect.