Hi we have a large lounge and on 3 sides there are double glazed windows and also a pair of double glazed doors, the room is 18 foot by 12 foot and the window drops are 5 feet then 2 and a half foot of brick to the floor, so a lot of window, when the weather is cold, this room is very cold in comparrison to the other lounge which only has the windows on one side, I would like to be able to use the other lounge all year around, but that means having the heating blaring and the rest of the house at boiling point, so can anyone tell me what can of benefit there would be in replaceing the glass with something more modern' the current units were fitted 12 years ago so I am hoping that technology will have moved on, all the tv programmes have houses with masses of windows, so I am i can find out what they use, any help would be appreciated as I rarely don't want to spend a fortune and not get a decent amount of improvement, Thanks