HC Deb 24 February 1975 vol 887 c59W
38. Mr. Spriggs

asked the Secretary of State for the Environment to what extent his Department has examined the real heat retention value of double glazing of housing, shops, industrial and commercial premises, &c.; and if he will make a statement.

Mr. Kaufman

The extent to which double glazing reduces heat loss has been known for a number of years as a result of work done by the Building Research Establishment and the industry.