In this work metamodeling approach is discussed for designing of lightweight steel frames and its roofing sheets utilizing advantages of the stressed skin action. In the first step, the roof construction is accurately investigated in terms of both stability and stiffness by solution of mixed shell-beam FE models. The combinations of loads on the structure are considered in accordance to relevant Eurocodes, with special emphasis on the lateral wind loads. Next, for the purpose of computational time reduction, metamodels are created by recently developed original code KEDRO. Finally, crosssection shape of corrugated sheets subjected to appropriate load combination is obtained by global stochastic search procedure to minimize maximal displacement of structure. The result is compared with standardized trapezoidal sheeting