Layout design optimization has a significant impact in the design and use of many engineering products and systems. The search of an optimal layout configuration is a hard and critical task and designers need specific optimization strategies to achieve it. These strategies have to be generic to be adapted to a maximum of layout problems and a maximum of designer's requirements. These strategies have also to be effective in the search of optimal solutions without being too time consuming. Then, this paper proposes a modular optimization strategy based on the genetic algorithm. This strategy is adapted to multi-objective layout problems, when the designer has to make a final decision on optimal solutions. The optimization modules are used in order to make the search of feasible designs easier, by taking into account the specificities of layout problems. The different algorithms, which result from the modular optimization strategy, are tested and compared on a realworld application. This layout problem deals with the search of an optimal spatial arrangement of components inside a shelter.