Assessment of Comfort and Intellectual Productivity in ZEB Energy-Saving Buildings

researcher's name
research field
Architectural environment/Equipment


In recent years, energy conservation has become the focus of global attention as efforts are made to control environmental pollution and realize a low-carbon society. In Japan, the civilian sector accounts for approximately 30% of the final energy consumption, of which businesses account for approximately 60%. With CO2 emissions increasing annually, it is imperative to conserve energy and reduce CO2 emissions of buildings. Measures are urgently needed, particularly for the vast number of existing building stock of small- and medium-sized enterprises (SMEs).
Furthermore, Japan faces severe electricity shortages as a result of the Great East Japan Earthquake on March 11, 2011. Further energy saving is thus needed in the operations of office buildings. However, energy saving in building operations, including lower lighting intensity and restrictions on the use of air conditioners and heating, could lower intellectual productivity. The challenge for office buildings today is achieving both energy conservation as well as comfort and intellectual productivity in the workspace.


Research is conducted on office buildings that are renovated to make them net-Zero Energy Buildings (ZEBs). Specifically, the effectiveness of the ZEB renovation work is examined by studying the changes pre- and post-renovation in the physical environment and employee satisfaction level. 


The research is designed to help provide clues to make existing general office buildings of SMEs ZEBs and to promote energy conservation renovations. Proposals will be made to further improve the buildings that we are studying.


In a questionnaire survey, respondents declared that intellectual productivity declined by 4.0% on average at the offices, comparing before and after the implementation of energy-saving measures. However, in a questionnaire survey that the author and others administered this fiscal year at general offices, respondents declared that productivity declined by 6.6% when before and after the implementation of energy-saving measures are compared. The rate of decline at the offices remained small in comparison.

purpose of providing seeds

Sponsord research, Collaboration research, Technical consultation


  • July 27, 2011, 14:00 (cloudy), desk surface illumination distribution
  • July 27, 2011, 14:00 (cloudy), plane temperature distribution
  • Level of satisfaction with various environments and the overall environment
  • Percentage change in intellectual productivity before and after renovation and before and after energy-saving measures
posted: 2014/05/21