Are ZEBs Changing the Face of Tokyo? A New Type of Building Combines Energy Efficiency and Comfort

One of the keys to realizing carbon neutrality may be ZEBs, which are being promoted by the Tokyo Metropolitan Government. What benefits of ZEBs can be realized in Tokyo, a city with a vast number of large-scale buildings?
Akasaka Intercity AIR, winner of the Energy Conservation Grand Prize’s Minister of Economy, Trade and Industry Award

Buildings Account for 70% of All CO2 Emissions

It is said that if we continue to emit greenhouse gases at the current rate, global average temperatures will rise by 1.5 degrees by around 2030. ZEBs (Net Zero Energy Buildings), which are being promoted by the Tokyo Metropolitan Government, are expected to play a key role in stopping global warming.

ZEBs are buildings that achieve zero or almost zero energy consumption through the use of self-sustaining energy sources such as solar power and advanced energy-saving technologies, significantly reducing energy consumption while maintaining a comfortable indoor environment.

The reason why ZEBs are so important is that, in fact, Tokyo's concentration of office and residential buildings is responsible for more than 70% of all its CO2 emissions. This is naturally a common issue for the world's major cities, and Europe and the United States are leading the way in ZEB conversions. Tokyo is also seeing an increase in the number of environmentally friendly buildings as efforts to convert buildings to ZEBs progress.

Akasaka Intercity AIR, a landmark in the Akasaka/Toranomon area, is a building complex that aims to achieve both energy conservation and business continuity, not only for its buildings but for the entire district. The buildings' exteriors, which function to block sunlight and provide natural ventilation, were consequently also utilized in countering the spread of COVID-19. In addition to saving energy and reducing CO2 emissions, the complex provides "smart wellness offices" that consider the health, comfort, and intellectual productivity of the people who work there.

In addition, Tokyo Metropolitan Archives, which was relocated and reopened in Kokubunji City in 2020, fitted out with double-layered exterior walls for heat insulation, solar power generation, and other state-of-the-art facilities, is attracting attention as a proof of concept for ZEBs in Tokyo.

Real Estate and Corporate Value Increase with ZEB Conversions

Even major construction companies are developing their technologies for ZEB conversions. Shimizu Corporation, which has been ahead of the industry in working on ZEBs, has developed an air intake slit in buildings that is effective in saving energy as well as preventing infectious diseases and that does not allow noise in. It has been adopted within design proposals for large-scale offices.

It is highly expected that the knowledge and technologies acquired by converting large-scale buildings into ZEBs will be applied to ZEB conversions for medium-scale buildings and others in the future.

On the other hand, converting large-scale buildings into ZEBs is more costly than conventional construction, and there are big hurdles to overcome in terms of technology and consensus building among tenants. However, for companies and property owners, the conversion to ZEBs should have significant benefits.

For example, more efficient energy use will improve employee comfort and productivity. In addition, buildings that are energy self-sufficient will surely show their strengths in the event of a disaster. A serious commitment to ZEBs will also attract the attention of domestic and overseas investors from an ESG (Environmental, Social, and Governance) perspective and lead to an increase in corporate value.

The Tokyo of the future, with widespread ZEBs, will surely become increasingly attractive as a place for people to gather.

Written by Onodera Fukumi / Translated by Amitt