The development of lattice design approaches using topology optimization to create complex lattice structures is the focus of ongoing research as the lattice structures show great potential throughout a wider range of research fields. Unfortunately, many of the methods suggested are often very difficult to industrialize due to their complexity and excessive computational costs in the design process. This paper proposes a novel framework of generating non-periodic lattice structures using topologically pre-optimized building blocks to improve the computational efficiency of the optimization process while maintaining the performance of the target structure and to make the process of obtaining optimal design more accessible for people with limited knowledge of topology optimization. The proposed method is comprised of two phases: the generation of a library holding optimized building blocks that can endure various loading conditions and the allocation of these building blocks at the proper location in the design space based on stress information obtained from the finite element analysis. Numerical examples are presented to show that the method is feasible and able to achieve reasonable performances, demonstrating its efficacy.