In this work a resource-saving technique is proposed for shape optimization of the thin-wall constructions by using metamodels in the form of local polynomial approximations. The technique is based on using the commercial CAD software as well as the original code EDAOpt developed in RTU for design of experiments, approximation and optimization. The technique considers designing of location of the control points of polygon of non-uniform rational B-splines for shape definition and building of the appropriate metamodels of responses for subsequent implementation of optimization. The technique is discussed on the base of solution of two test problems. The first is concerned with shape optimization of plate bending problem with displacement constraints and the second – of plate biaxial tension problem with stress constraints. Efficiency of three procedures of the shape definition is analyzed. It is shown that utilization of proposed technique and definition of shape by procedure of the polygon control points of non uniform rational B-splines give best results. These results are better than results obtained by classical homogenization method.