It includes the rural parts of Stirling now being done in addition to the original plan for the whole city, the whole of the Orkney Isles and the remaining parts of the Western Isles. The measures will cut average energy bills by £61 a year and by £2,445 over the 40 year lifetime of the insulation. Top-ups will be offered free to everyone who already has loft insulation that is not up to the recognised standard. A third of all the heat lost in an uninsulated home is through the walls. Typically, a quarter of the heat in an uninsulated home is lost through the roof.