The average power consumption for the residential sector in Indonesia is quite high. It makes sense to reduce consumption by applying the near Zero Energy Building concept. The retrofit strategy is one strategy for combining energy efficiency and cost-effectiveness. PV system equipment selection will impact directly to generated power, need to be optimized. On the other side, load equipment selection also needs to be optimized for energy consumption efficiency. In this research, minimizing the retrofit cost and find a 'cost-optimal' package, energy efficiency technologies and Renewable energy generation systems be combined and investigated. Equipment selection for lighting, space cooling, and general appliances type held based on cost per load energy and equipment price. The preliminary result of this study was a mathematical model from optimization of the combination of appliances types, PV Modules types, and minimum PV system capacity to achieve a cost-optimized nZEB.