In this paper, the metaheuristic algorithms such as Flower pollination and Harmony search algorithms are proposed to optimize the sizes of the steel components at the elevated temperature dealing with EN 1993 1-2. The purpose of these algorithms inspired by nature is to obtain the appropriate cross-section properties of the welded I sections. Numerical examples from the literature consisting of the protected steel structural components have been resized under different fire situations such as 30-, 60- and 90-minutes fire time. Based on the results from the numerical examples, the effect of the fire protection materials on the objective function (total weight of the steel structures) is quite high and the reduction of the total cost is almost 30% compared with the other studies. In addition, one of the most important duties of civil engineers, ensuring the balance between economic efficiency and safety, is fulfilled in a short time with the aid of the metaheuristic algorithms.