Mitsubishi Electric ZEB-related technology demonstration building "SUSTIE"

■ Four key points of "SUSTIE," which presents the "prototype architecture" that society will need in the future

In order to achieve a carbon-neutral society, the widespread adoption of ZEB (Zero Energy Buildings) is an urgent issue. At the same time, in anticipation of a declining workforce, creating comfortable workspaces that contribute to the health and productivity of office workers is a crucial theme for future office design. "SUSTIE" is an architectural concept that aims to solve these social issues simultaneously, achieving the highest level of balance between energy efficiency and health/comfort.

1) A design approach that anticipates the widespread adoption of 'ZEB' in urban areas.
While ensuring users feel "comfortable" is crucial for the widespread adoption of buildings, increasing ventilation, lighting, and other equipment to achieve this increases power consumption, which goes against energy conservation efforts.

Therefore, in "SUSTIE," we first focused on maximizing the use of natural energy through "architectural ingenuity" (passive design), such as ① installing openings to take in natural ventilation and shading from sunlight with eaves, thereby reducing energy consumption. Then, we achieved thorough energy conservation through a step-by-step design that combined this with ② the introduction of "high-efficiency equipment" (active design).
Furthermore, in order to achieve ③ "Maximizing on-site energy creation," we installed all of the solar panels (approximately 360 kW) on the building, demonstrating the feasibility of achieving "ZEB" (Zero Energy Building) for medium-sized buildings in urban areas with high site constraints.

2) Architectural innovations: Reduce energy consumption through the active use of natural energy.
The large atrium space on the north side ensures brightness through natural light from the north, eliminating the need for artificial lighting during the day. By utilizing heat retention at the top of the atrium and gravity ventilation through natural ventilation windows, the air conditioning load throughout the building is reduced.

3) Introduction of High-Efficiency Equipment: MEP Engineering that balances ZEB (Zero Energy Building) and wellness.
In some offices, a "ceiling chamber type air-based radiant air conditioning system" has been introduced, which cools and heats the ceiling cavity with packaged air conditioners and uses the radiant effect of aluminum ceiling panels to regulate the room temperature without creating a feeling of draft. This equipment plan, which balances thorough energy saving with improved comfort for office workers, is being implemented throughout the building.

4) Operational Initiatives: An innovative "ZEB operation" that balances energy saving and comfort using AI.
Using a digital twin environment built based on BIM data from the design phase, we simulate the operation of each piece of equipment, as well as temperature, humidity, and illuminance, in advance to predict the impact on energy efficiency and comfort. Furthermore, by combining this with multi-purpose optimization technology utilizing AI, we formulate and execute optimal operational plans, realizing "ever-evolving architecture" that leverages data obtained from actual operation for subsequent considerations.

Furthermore, at "SUSTIE," Mitsubishi Electric and Mitsubishi Jisho Design jointly demonstrated a "human location information detection service ^*5." This initiative supports Activity-Based Working (ABW) for office workers while contributing to both energy saving and comfort.

Through these efforts, "SUSTIE" has achieved "ZEB" status in terms of actual annual energy consumption. Furthermore, with the goal of reducing overall CO2 emissions related to the building, we are working not only to achieve "ZEB" status during operation, but also to reduce embodied carbon ^*6 by reducing equipment capacity, reducing refrigerant usage, and facilitating equipment replacement.

^*5 A system in which the air conditioner communicates with terminals held by people inside a room to obtain location information and displays the location of the people inside and information about the thermal environment of the room on an indoor map.
^*6 This refers to the CO2 emissions from all activities other than energy and water consumption during operation, out of the total CO2 emissions throughout the entire lifecycle of a building, from material procurement to construction, operation, and demolition.

Technology deployment in "SUSTIE"

We will introduce an example of "SUSTIE" technology and space, which incorporates equipment that leads to improved wellness into a design process that combines architectural ingenuity with highly efficient facilities and equipment.

Announcement of related book publication
Our company, in collaboration with Mitsubishi Electric Corporation, participated in the editing of the book "Shinkenchiku" (New Architecture). 2026 year 2 4 ozoni sang ZEB + Beyond Zero Energy ZEB and WELL Mitsubishi Electric achieves both. SUSTIE "but 2026 year 2 month 26 It was released on [date].
This book is by Mitsubishi Electric. ZEB Related Technology Demonstration Building SUSTIE This issue features a comprehensive explanation of technological integration aimed at achieving both energy efficiency and comfort, which are essential for urban offices of the future. Experiments are conducted daily in what is known as a "living lab." SUSTIE This book offers insights into the future of offices and their potential, based on our experiences.