There are large variations in circumstances such as the design of the house and heating system, and in living patterns, which can produce a wide range of heat losses through different parts of the building, but estimates have shown for example that the approximate percentage heat-loss for a typical uninsulated between-the-wars semi-detached house, heated to whole house central heating standards, can be as follows:
Per cent. Heat-loss through walls 35 Heat-loss through roofs 25 Heat-loss through floors 15 Heat-loss through windows 10 Heat-loss through walls 15
§ Dr. John Cunningham
The following table shows the estimated number and percentage of homes in Great Britain, at December 1976, that have no domestic hot water storage tank insulation and those with insulation below 3 inches. These estimates are provided by Audits of Great Britain.
000s Per cent. Total homes 19,020 — Total homes with hot water tanks 16,198 100 Homes with uninsulated hot water tanks 3,965 24 Homes with hot water tanks insulated below 3 inches 8,033 49
On 12th December my right hon. Friend announced a number of energy conservation measures, including a 10-year programme to install hot water tank jackets and other basic insulation in up to 2 million public sector dwellings. The Department took the lead in the discussions which led to the circulation in November 1977, for comment by 31st January, 1978, of a draft British Standard for lagging jackets. I hope that there will be early agreement on a British Standard.
The Department will continue, through the Save It publicity campaign, to encourage the installation of lagging jackets of adequate thickness in private sector homes; and will specifically encourage the purchase of lagging jackets to the British Standard, when agreed.