An optimum design of low-cost housing offers low-income urban inhabitants great opportunities to obtain a shelter at an affordable price and acceptable indoor thermal conditions. In this paper, the design and operation of a low-cost dwelling were numerically optimized using a simulation-based approach. Three multi-objective cost functions including construction cost, thermal comfort performance, and 50-year operating cost were applied for naturally ventilated and air-conditioned buildings. The thermal environment inside the house was controlled and assessed by two thermal comfort models.