Different structural materials invariably provide differing reactions and resilience to heat and the effects of fire. For example reinforced concrete, inherently achieves a greater resistance to fire (although for longer fire duration, increases in reinforcement cover may be required), than steel. To improve resistance to fire materials can be protected by insulation to prevent them reaching the point where it fails and results in the structure collapsing.
However, methods of protection (such as insulation) can be expensive and have an undue impact on the aesthetics and intended look and feel of a building.