This paper targets the optimal combination of design and operational measures in a new design or retrofit project with the aim to reduce demand charges. To achieve this goal, this paper introduces an approach based on the analysis of all feasible energy consumption and peak reduction measures in an office building under different utility rate structure. The analysis includes all measures that are commonly adopted to decrease energy consumption and demand charges, specifically energy efficient measure and energy flexibility measures. The outcomes suggest the optimal combination that minimizes demand charges in commercial buildings.