Before and after illustrations showing how secondary glazing changes comfort, draughts, condensation and heating performance on a cold day.
Cold day: scenario 1
This room has the radiator located in the wrong place. The correct place would be under the window.

Cold day: scenario 2
This room has the radiator in the correct place. The secondary glazing will be especially effective in rooms with tall ceilings.

Notes about condensation
Condensation is very much a factor of how much moisture is in the home, corresponding to the activities and number of people living there. Two people living in a large house might not experience much condensation.
When behind thermal blinds and shutters, secondary glazing will cool overnight because it is denied the warmth of the room. You may see condensation when you open them in the morning.




