IBEC 建築省エネ機構(一般財団法人 建築環境・省エネルギー機構)

About us

In order to contribute to the achievement of the Sustainable Development Goals (SDGs), Institute for Built Environment and Carbon Neutral for SDGs (IBECs) conduct a variety of research, technological development and outreach activities related to housing, architecture and cities, including the built environment and energy conservation.

Activities and Achievements (excerpt)


BEST (Building Energy Simulation Tool) is an effective computer simulation program for building energy research and evaluation. BEST is capable to analyze not only the performance of building envelope and HVAC system, but also lighting, water use, and additional equipment loads such as elevators.


CASBEE (Comprehensive Assessment System for Built Environment Efficiency) is a method for evaluating and rating the environmental performance of buildings and the built environment.
CASBEE has been designed to both enhance the quality of people's lives and to reduce the life-cycle resource use and environmental loads associated with the built environment, from a single home to a whole city. Consequently, various CASBEE schemes are now deployed all over Japan and supported by national and local governments.


J-CAT (Japan Carbon Assessment Tool for Building Lifecycle) is a tool (calculation software and manual) developed by the Zero Carbon Building Promotion Committee to calculate GHG (greenhouse gas) emissions, including CO2, throughout the entire building lifecycle. Its first edition (2024 trial version) was published in May 2024.

Overview of IBECs

Name Institute for Built Environment and Carbon Neutral for SDGs
Representative Director TOSHIHARU IKAGA,President(profile
Location HB Hirakawacho bldg. 2-8-9. Hirakawacho,
Hirakawacho, Chiyoda-ku,Tokyo,102-0093 Japan
TEL:+81-3-3222-6681 FAX:+81-3-3222-6696
Date of foundation March 28, 1980