A shape annealing approach to truss topology design considering the tradeoff between the mass of a structure and multiple members of the same size, called a class of members, is presented. The problem of optimal grouping involves finding a structural design with an optimal number of classes and the optimal sizes of those classes; cross-sectional area is considered as the measure of size in this paper. Multiple members of a uniform cross-sectional area is advantageous when considering the cost of purchasing and fabricating materials to build a structure. The shape annealing method (Reddy and Cagan 1994) is used as an approach to solve this problem by incorporating a method for dynamic grouping of members into classes and adding a constraint for the number of allowable classes. This method is demonstrated on arch and truss problems. As well, results from an imposed symmetry constraint for the truss problem will be shown.