In this work, it is proposed a new method for the optimization of hollow block shape by using the metamodeling technique. The method is based on using the commercial CAD software SolidWorks as well as the original code EDAOpt developed in RTU for design of experiments, approximation and optimization. The method is discussed on basis of practical problem. The hollow block shape is searched with consideration of material consumption for strength and thermo insulation. Single block is used for thermal model which take into account heat conduction of block materials and convection process on block external wall. Single block model with different boundary conditions and wall models with different stacking are used for strength calculations. Internal cutout shape of block is defined by smooth spline line that is given by 7 control points. At the beginning, disposition of control points are planned. Further computer experiments with finite element software are implemented. The obtained responses are approximated and then used for optimization. As result of optimization an alternative cutout shape is obtained which save ~8% of block material. In comparison with method of homogenization, the developed method essentially decreases necessary computation resources