The studied facility is a nine-story office building with a total floor area of 71,500 square feet. The building receives both steam and chilled water from an energy company while hot water is generated through steam-water heat exchangers in the building. The interior zones from the 4th floor to the 9th floor is initially served by one constant volume (CV) air handling unit (AHU) system with electrical reheats at each terminal box while the exterior zones is initially served by a constant volume primary AHU system with a 2-pipe hot water/ chilled water induction unit system. The low levels of the building are served by one constant volume AHU system with electrical reheats at each terminal box. The excessive fan power and electrical reheat, chilled water was used in the building. Continuous Commissioning (CC™) was applied to solve existing facility problems, to optimize facility operation, and to reduce operational costs. The CCTM measures include AHU variable air volume (VAV) conversion, AHU economizer optimal control, integrated AHU fan speed and supply air temperature control, integrated operation between interior zone and exterior AHUs, chilled water system return temperature optimal control. This paper presents detailed CC™ measures and results of this integrated system optimization study.