The construction of concrete shell roofs in Mexico has declined owing to seismic vulnerability and slenderness effects. Traditional form-finding guarantees static equilibrium under self-weight alone and remains inadequate under seismic demand, where stiffness degradation and stress reversal govern the response. Three form-found anticlastic shells with four, six and eight supports were generated by the force density method, which yields compression-dominant configurations before reinforcement is defined. Reinforcement was first designed with the Eurocode 2 three-layer sandwich model, which neglects the compressive contribution of the reinforcement; a nonlinear multilayered formulation was then adopted to resolve the stress state through the shell thickness. Design actions followed NTC-2023; the analyses incorporated initial geometric imperfections, nonlinear buckling, the Takeda hysteretic model and synthetic accelerograms for Mexico City. The shells developed controlled, low-level nonlinear behavior, with compression governing the response and the reinforcement carrying a significant fraction of the compressive demand under stress reversal. Eigenmode-affine imperfections reduced the ultimate capacity by 45.2% to 22.1%, the reduction diminishing with the number of supports: more petals stiffen the shell and raise its capacity, at the cost of ductility. Since imperfections consume so large a share of that capacity, recovering design margin becomes decisive: accounting for the compressive contribution of the reinforcement reduces the required area by 10%, making the multilayered representation a design requirement rather than a refinement. The numerical cracking patterns coincide spatially with the damage documented after the 2017 earthquake in Félix Candela’s Los Manantiales restaurant, supporting a framework transferable to other earthquake-prone regions.
