A Student-Driven Net Zero Energy School / Mizunamikita Junior High School

A student-driven Zero Energy School initiative
Mizunamikita Junior High School, positioned on the south-facing slopes of a hill overlooking Mizunami City, stands as a pioneering project that has achieved the status of the first Net Zero Energy Building (ZEB) for an educational institution in Japan. Certified as a Super Eco School by the Ministry of Education, Culture, Sports, Science, and Technology, it achieves zero energy consumption by reducing 50% of its energy use through energy conservation and meeting the remaining demand with renewable sources, such as solar power. To provide opportunities for environmental education through trial and error, a number of eco-friendly tools that can be operated by students are installed in the school.
The significance of transforming the school into an eco-conscious architectural model extends beyond merely optimizing energy efficiency to reduce running costs. Daily interactions within a building embedded with green technologies fosters respect for the environment. The ultimate purpose is environmental education, which cultivates a sense of stewardship and proactive behavior in students. With that said, every standard classroom is furnished with eco-monitors, which are display devices that show environmental data for the entire school and inside the classrooms. These monitors allow students to check indoor and outdoor air conditions, as well as the immediate impact of actions like turning the lights on and off or modulating windows. This framework empowers students to deepen their understanding of the environment while encouraging them to make conscious decisions on a daily basis. Post-completion, the combined effect of the building design and student-led initiatives resulted in the school attaining Net Zero Energy status for the year from September 2019 to August 2020.
We believe that if graduates later become active around the world, proliferating actions toward the conservation of our planet, this influence will significantly surpass the environmental benefits achieved through automated energy savings in a single school, thereby contributing to broader environmental improvements.

Maximizing the use of topography and location
The buildings harmoniously extend across the land, making thoughtful use of the topography and location. Positioned to follow the mountain’s incline, the two and three-story school buildings with sloping roofs are designed to blend in with the surrounding landscape, providing stunning views of the city and mountains from the top-floor classrooms.
The campus consists of three separate buildings and a gymnasium encircling a courtyard. The south building is placed at a 10-degree angle, opening up the courtyard and channeling the mountain’s breeze inside. The air is cooled by the planted trees and distributed throughout the premises. Although each grade has its dedicated building, special classrooms are located across the complex with communal spaces such as the learning commons and multipurpose areas in the center, to foster both a cohesive and communal educational experience.
The structure height is kept at 3.35 meters to ensure expansive views over the city to the south of the north building. The architecture features a minimalist concrete frame of 350mm width, formed by slender columns and unbonded PC slabs, creating a strong yet refined facade.

A “wellness school” with an emphasis on the living environment
Standard classrooms, where students spend the majority of their school hours, were all strategically placed on the highest floors to offer the best views. Natural lighting from the north and south, natural ventilation using the differences in window height, and an interior of wooden beams and finishes provide a calm and comfortable learning environment. The roof is also made of local timber, enveloping students in a warmly designed interior.
Features that allow students to experience the environment through all five senses are scattered throughout the school. There is touchable insulation to understand its effect and installations like ribbons or thermometers in the cool pits. Furthermore, instruction manuals for the school and eco-tools have been prepared and distributed to the students. Focused efforts, especially by the Environmental Committee, led by students, are underway to facilitate engagement in achieving a Net Zero Energy School.

Community-centric design featuring “Mizunami's uniqueness”
The design keenly preserves “Mizunami’s uniqueness” by enthusiastically embedding the philosophy of local production for local consumption into its architecture. The facade tiles are crafted from clay found near the city and kiln-fired in a local facility, representing materials that resonate deeply with the community. For the wooden finishes seen throughout the building, wood was harvested from Mizunami City and the larger Gifu Prefecture. Environmentally friendly features include a wind tower shaped after a climbing kiln, Mizunami’s ceramic heritage, for natural ventilation, a spiral staircase serving as air intake for the cooling and heating trench inspired by locally excavated ammonite fossils, and the gymnasium’s solar heat-collecting roof in the shape of a whale. A workshop involving the students was conducted during the construction phase where they crafted mosaic tiles in relief of the whale fossils found at the site, fostering a sense of ownership and expectation towards nurturing the school in a better direction.

Project Details

Project name: Mizunamikita Junior High School
Purpose: Junior High School
Location, Mizunami City, Gifu Prefecture, Japan
Site area (m2): 16,132.26
Total floor area (m2): 8,090.07
Number of floors: 3 floors above ground
Eave height / maximum height (m): 9.23 / 14.45
Main structure: Reinforced concrete structure, partially wooden, steel structure
Completion month/year: December 2018

Credits

Client name: Mizunami City
Lead architect: NIKKEN SEKKEI LTD
Main scope: Concept design, schematic design, design development, site supervision
Construction Contractor: GIKEN, Nakashima Corporation, Seikyo Co., Ltd.
Photo credit 1: Tamotsu Kurumata
Photo credit 2: KINDAIKENCHIKU-SHA CO., LTD.