In association with NCCI: Design of reinforced concrete filled, hot finished structural steel hollow sections in fire PN006a-GB. Localised resource for UK NCCI: Design of reinforced concrete filled, hot finished structural steel hollow sections in fire The UK National Annex to BS EN 1994-1-2 recommends that informative Annex H (Simple calculation model for concrete filled hollow sections exposed to fire all around the column according to the standard temperature-time curve) should not be used. This NCCI document provides alternative guidance. March, 2014