http://www.energyefficiencynews.com/articles/i/5311/?cid=3

Japanese contractor Shimizu has completed work on a building in Tokyo that it claims will emit the least amount of CO2 in the world.

The company's new headquarters building on Kyobashi, Chuo-ward, which opened on August 1^st, emits only 38 kg/m² of CO₂ per year, 62% less on average than ordinary buildings in Tokyo.

The building uses various technologies to reduce emissions, including an air conditioning system that makes use of radiant heat.

The system uses water pipes running under ceiling boards like capillary vessels to absorb heat from people working in the building through a radient effect. The technology can reduce CO₂ emissions by 30% compared to a conventional air conditioning system.

Shimizu has also installed LED lighting controlled by motion sensors, powered by solar photovoltaic panels in the outer walls during the day.

The solar panels cover around 2000 m² on the exterior of the building to generate 84,000 kWh per year.

The building also uses automatic window shades that follow the angle of the sun to allow in as much natural light as possible.

The company says that fine-tuning the various systems will enable it to reduce CO₂ emissions by 70% by the end of 2015, and it will offset the rest.