N.B. This report was replaced by a 2nd edition in 2003 and a 3rd edition in 2013.

The application of external thermal insulation is a technique relatively new to the UK. The use of appropriately designed systems particularly on walls of high rise buildings provides an attractive method of energy conservation. To identify the design principles affecting the safety of occupants and the probable extent of fire spread, BRE has conducted large-scale tests in a four-storey experimental building. The rig was insulated externally either by direct application of a range of insulation/weathering systems or by a ventilated cladding system. An insulated timber cladding system typical of current accepted practice was used as the basis for comparison. A series of fundamental design recommendations has consequently been drawn up to minimise the hazard to life and to restrict the extent of necessary reinstatement following a serious fire. (Summary)