HC Deb 23 February 1989 vol 147 c727W
Mr. Matthew Taylor

To ask the Secretary of State for the Environment if he will set out the procedure for approving the thermal conductivity of insulation materials as satisfying the requirements of the building regulations, and the respective roles of CIBSE, the BBA and the BSI in such a procedure.

Mr. Trippier

Part L of the Building Regulations 1984 (in its current form) requires the calculated rate of heat loss from various parts of the exposed fabric of a new building to be within certain prescribed limits. The enforcement of these requirements is a matter for the building control authority. Practical guidance is provided in approved document L "Conservation of Fuel and Power", but the advice given in this document is not mandatory.

The approved document advises that information about the thermal conductivity of a product should be obtained from the supplier or manufacturer, or that a value should be obtained from table A3–22 of the Chartered Institution of Building Services Engineers guide. In the case of certain products, the approved document also advises that a test certificate should be obtained. The use of materials which comply with an appropriate British Standard or which are certified by the British Board of Agrement is another way of demonstrating that the requirements of the regulations have been met.