Revise GCSE Physics

Question:What is usually the least cost effective form of home insulation?

Most often double glazing is the least cost effective because of it's very high initial cost and relatively low annual savings.

Remember that heat is still lost through double glazing as radiation.

Recall the thermogram picture of a house.

The windows always look warmest; but of course what we were seeing was the heat loss through the window from the warm room.