While Otemachi has historically been developed as a central business area of Japan, it is required to further improve its value as an international business town. New headquarters of Japan Post Group in Otemachi Place were relocated from Kasumigaseki in 2018. From the planning stage, we aim to construct an office space with consideration for sustainability and work-environment, to obtain LEED certification, and to adopt various methods as shown below. There are a couple of subway and JR stations within walking distance of 800 meters from Otemachi Place. Selection of good location, where public transportation is easily accessible, makes it possible to reduce use of cars, and eventually leads to a reduction of CO2 emission. Latest models of LED lamps have been installed on all the floors of office space to optimize energy performance (lighting power). The installment of LED lights has made it possible to achieve over 30 percent reduction of energy against the baseline of lighting power density that is allowed by ASHRAE 90.1-2007. In this Project, all fluorescent lamps which contain mercury have been replaced by LED lights. Japan Post Holdings has already purchased renewable energy certificates (REC) for two years, each equivalent to the 50 percent of annual energy consumption in the office space. In this project, office, cafeteria, large conference room and all commonly used spaces are designed to ensure all workers should feel that temperature and humidity are comfortable. The plan of the Project is designed so that the environment will be maintained through appropriate inspections and operations. The project utilizes stormwater and recycled water for hygiene facility. Further, the project installed hygiene equipment with efficient water-saving function in tenant space. Thanks to these efforts, the project succeeded in water saving by approximately 50 percent below the level set by LEED, enabling to win full points in this category. Japan Post Holdings implements comingled recycling of wastes, which include items LEED requires to collect separately. Under the Construction Waste Management Plan by Japan Post Holdings, we decided not to incinerate/landfill the construction wastes produced during the construction works of Otemachi Place, in an aim to boost recycling of such wastes. In this project, not only fundamental commissioning, but also enhanced commissioning, which checks wider array of items has been conducted. Commissioning is a mandatory itemfor LEED projects, so that environmental capacity of projects should be achieved fully in a transparent method.