Double glazed windows are named as such because of its two panes of glass in between the frame. One type of design is Sash windows – read more here: http://www.sashwindows-prices.co.uk/prices-guide/
A gap within these panes is filled with air for insulation to keep the heat and cold inside the home. This made these windows very cost efficient.
These windows also have a wide range of styles and can be fitted to a variety of window types like casement, sliding, double and a lot more. The double glazed windows can be made of wooden material, UPVC or aluminium. These windows are cost efficient not only because of its ability to save energy but because it is not difficult to keep in a good condition.
There is no need to repaint it every year. Installing it can be done by hiring contractors or if you are a handyman, DIY method can be done too.
Double glazed windows are often the best choice for windows for convenience, comfort, security and style.