In general, large-scale space frames, such as stadiums and gymnasiums, have a role as an evacuation facility. However, some accidental falls of a ceiling and equipment during an earthquake have been reported, and these accidents might cause human injury or casualty. On the other hand, these structures often have an aesthetically elaborated design, but they do not always have high performances from a structural point of view. This research proposes a method to support designing a large-scale space frame, which implements: 1) a design elaborated by an architect and 2) structural and control performances, which can reduce damage or fall of a ceiling, on the basis of simultaneous optimization of structural and control systems. The number of design parameters in the optimization problem is reduced by describing the roof shape with a Bézier surface. The genetic algorithm is used for the optimization.