Bellevue School District responded to Washington State's mandate that schools must achieve a minimum benchmark level of performance and sustainability by partnering with NAC|Architecture to design Eastgate Elementary School, a 64,000-square-foot energy-efficient school in Seattle. Additionally, the School District desires that its buildings reflect a high state of awareness and respect for the principles of sustainability. NAC also seeks to uphold the principle that the true value of a building is experienced in the total cost of ownership. Energy purchased to operate a building is growing in significance and now constitutes the highest cost in the life cycle of many buildings. For that reason, energy conservation is a primary objective of NAC.
Early in the design process, an eco-charrette was held with representatives of the capital projects department, maintenance staff, school administrators, and the architectural/engineering team. This meeting established that energy efficiency was a high priority for the school and community. NAC and Bellevue adopted EPA's Target Finder as the tool for judging their success in setting superior energy performance goals and evaluating design options. Both the architect and the owner believed that the ENERGY STAR program provides an objective and nationally recognized method of measuring and meeting expected performance goals. Eastgate Elementary rated 82 out of 100 in Target Finder, thus achieving Designed to Earn the ENERGY STAR.
The Bellevue community recognizes the importance of efforts to control the negative effects of global climate change as well as the economic significance of future building energy and operating costs. The voters of Bellevue School District support the creation of energy-efficient and sustainable schools, and Eastgate Elementary helps fulfill this objective. The design has advanced energy conservation and sustainability efforts in the area.
Energy-efficient design elements of the building include a ground source heat pump system that will utilize the heat sink of soil beneath playfields for heating and cooling. The thermal envelope is thoroughly insulated to minimize conductive heat loss and uncontrolled infiltration. Glazing has been optimized to provide ample natural lighting, and glass qualities have been specified to reduce conductive and radiating heat transfer. Lighting is controlled separately at the perimeter, and occupancy sensors turn off lights when appropriate. An Energy Monitoring and Control System also allows tracking and regulating of energy consumption and comfort conditions. In addition, a thorough commissioning process is planned to ensure that systems are working as designed.
Architect of Record:
Engineering Economics, Inc.
Bellevue School District
Design Rating / % Energy and CO₂ Reduction*:
82 / 28%
Design / Completion Date:
2008 / 2009
Estimated Energy Use
Estimated Total Annual
Estimated Annual Energy Cost:
Ground source heat pump system, thoroughly insulated thermal envelope, glazing, daylighting, occupancy sensors, Energy Monitoring and Control System.
For More Information:
Colin R. Jones, AIA
*Percent Energy and CO₂ Reductions are compared with an average building of similar type.