Fire protection costs in composite buildings for cost-benefit analysis of fire designs

As performance-based design approaches are increasingly emerging as alternatives to prescriptive designs for buildings under extreme hazards, the economic impact of adopting the former over the latter needs to be assessed. Here, we describe a method for quantifying the costs of fire protection in composite steel frame structures under different fire designs. A cost database is constructed for 130 prototypes of steel framed composite buildings with different occupancies, dimensions, and fire ratings using a commercial cost estimator. The cost of passive fire protection on steelwork is found to range from 0 to 1.20% of the total construction cost for composite buildings with sprayed fire resistive material in the United States. A generalized method is then developed to evaluate fire protection costs in composite buildings, including the effect of different structural fire designs such as the optimized allocation of fire protection through performance-based fire design. The method is applied to a case study of a 15-story office building to compare the costs associated with fire protection for three designs. The method can be incorporated into a cost-benefit analysis to evaluate the lifetime economic impact of various structural fire designs. •A cost database is provided for 130 steel-concrete prototype buildings.•Fire protection costs between 4% and 12% of total construction costs in composite building.•Passive fire protection cost on steelwork amounts to up to 1.2% of total construction cost.•A method is given to evaluate the cost of fire protection based on the composite building's design.•This can serve for cost-benefit analysis of performance-based structural fire design.