The building, which will be fully open tomorrow, is the new Shimizu headquarters and is located in Tokyo. The building emits only 38kg/m2 of CO2 per year, which Shimizu said is 62% less on average than ordinary buildings in Tokyo. Japan’s lack of oil or gas means that buildings there are designed to conserve energy, said Shimizu, and it expects to see an increase in demand for construction of buildings like the new Shimizu Headquarters.
Shimizu has developed and adopted various technologies to reduce CO2 emissions, including an air conditioning system that makes use of radiant heat. Water hoses run under ceiling boards. By controlling the temperature of the water circulating in the hoses, the temperature of the celling board surface is controlled. As a result, a surface temperature of about 20°C absorbs the heat of people working in the office through a radiant effect. This system can reduce CO2 emissions by 30% compared with conventional air conditioning systems, said Shimizu.
The lighting system also makes use of energy-efficient technology. Light-emitting diode lighting is fully adopted and controlled by motion sensors. Energy used for lighting in the daytime is generated by photovoltaic panels placed in the outer walls. The area of the PV panels is about 2,000m2 and generates 84,000kWh of power per year. Furthermore, Shimizu has installed window shades whose shade angle automatically changes to follow the sun and optimise natural light. These efforts make it possible to reduce CO2 emissions by 90% compared with standard lighting systems.
By the end of the year 2015, Shimizu said that it will reduce CO2 emissions down to 70% through fine tuning of air conditioning and lighting facilities as well as adopting further energy saving systems.