Draught Heat Loss Calculator
Heat loss through “air changes” - air flowing out of a house through draughts, vents and holes - is huge. An old and unimproved house might have 4 air changes every hour. For a typical 3 bed house on a cold 0 degree C day, that means 6 - 8kW being lost through leakage alone. Use this interactive calculator to estimate how much heat is being lost in your house.