The answer to this question is dependent on the type of home you have and what energy efficiency measures you already have in place, if any.
Heat gains come mainly from heating systems, but also from solar gains, appliances and body heat. This heat can then be lost through walls, the roof, floors, windows and doors and ventilation systems.
Typically, 30-35% of the heat will be lost through uninsulated walls, 20-25% through the roof, around 15% through windows, 15% through leaky ventilation, 10% through the floor and 5% through doors.
These figures are only a rough guideline and change if you live in a flat or in a particularly old draughty house. Similarly, if you already have some loft insulation for example, the heat loss through your loft will be much lower, and a higher percentage will escape through the walls or other areas.
We believe that although it’s important to know where in particular you are losing heat, installing energy efficiency measures has to be looked at with a whole house approach. Although wall insulation is usually very beneficial, if you have very old draughty windows, the heat will still escape through them, or through an uninsulated roof.
If in doubt, we can offer advice on the most cost effective energy improvements to your home. The consultation and assessment is free if you choose us to install the energy efficiency measures.