Recently, a policy named COOLBIZ has been executed in Japan as a measure against global warming. The policy suggests raising the preset cooling temperature in the office from 25°C to 28°C and wearing lighter business clothing. However, it is a concern that higher temperatures might negatively affect the office workers' performance and cause economic losses. Therefore, the office environment should be evaluated not only by the amount of energy conservation but also by the economic effect. In this research paper, productivity and ecoefficiency of three kinds of remedies for the office conditions during the COOLBIZ campaign were calculated: (1) setting back to a traditional office condition, (2) using additional individual cooling items, (3) installing different HVAC systems. From analysis, it was estimated that installing a task/ambient system using a radiant cooling system with membrane fabrics was the most effective from both perspective of the economic effect and the energy conservation.