uPVC? Unplasticised Polyvinyl Chloride - Unplasticised PVC – UPVC

Double glazed windows and doors help to;

-Provide a barrier against the elements.
-Keep heat in and reduce household heating bills.
-Ensure your house is better protected with Top Security Features.
-Help to increase the value of your home.
-Keep Appearances Up.
-Are Easy To Clean.
-Helps to reduce outside noise.

Website created by 837 designs.
A double glazed window is effectively two panes of clear glass separated by an air gap.
Double glazing, compared to single glazing, cuts heat loss in half due to the insulating air space between the glass layers.
In addition to reducing the heat flow, a double-glazed unit with clear glass will allow the transmission of high visible light and high solar heat gains separated by an air gap.
"Your local Double glazing company"
Do you have condensation in your windows?

One of the most common problems with double glazing is when condensation begins to form between the two panes. 

When the sealed units are manufactured the air gap usually contains dehydrated air, or inert gases, and the spacer contains a silica gel which drys out moisture.

Over time, the seal can back down somewhere around the unit, moisture is let in, and once the gel has absorbed as much moisture as it can - condensation begins to form between the two panes of glass.

The only way to solve this is to replace the sealed unit.