§ Mr. Rostasked the Secretary of State for the Environment what is his latest estimate of the minimum economic U values for roof and wall insulation; and how these compare with existing building regulations.
§ Sir George YoungI have no estimate of minimum economic U value. Maximum U values for roof and wall insulation stipulated in the building regulations in England and Wales take account of cost effectiveness and of practical consequences for building design and construction. They are:
U Values Walls All buildings (except factories and storage buildings) 0.6 W/M 2° C Walls Factories and storage buildings 0.7 W/M 2° C Roofs Domestic buildings 0.35° C Roofs Non-domestic (except factories and storage buildings) 0.6 W/M 2° C Roofs Factories and storage buildings 0.7 W/M 2° C