October 21, 2014, by Jeff Parker

Designing for Energy Efficiency

Achieving peak energy efficiency in building design rarely involves just one single “Silver Bullet.” Rather, it requires a number of interrelated strategies that together take full advantage of every opportunity to conserve energy.

Featured recently in School Planning & Management magazine as a model of design for sustainability, the combined Coy Middle School/Trebein Elementary campus SHP designed for the Beavercreek School District is a prime example of how an integrated design approach can dramatically affect energy efficiency.

As we shared in our last post, an independent energy audit of the new campus revealed that the district will realize $150,000 in electricity savings annually, earning a record $492,000 energy rebate from Dayton Power & Light (DP&L). Here are some of the strategies we incorporated into the design to achieve the historic energy conservation milestones:

  • Combining two separate schools into one single campus created several economies of scale advantages. While still achieving the district’s need to give the schools separate identities, we were able to enhance efficiency by sharing a geothermal system, sanitary and water taps, electrical systems, kitchen and other key infrastructure components.
  • The two-school complex, along with ample available land on the 50-acre campus, made investing in a highly efficient geothermal HVAC system feasible.  The geothermal system is projected to consume up to 30% less energy than a conventional system while also reducing related maintenance and replacement costs.
  • Insulated concrete form (ICF) walls compose the structure of the building.  ICF walls are a system of rigid, insulated foam blocks reinforced with steel and filled with concrete that have a high thermal resistance value. The insulation they provide reduces heat loss and contributes to further energy savings. Triple-glazed glass windowpanes that are separated by an air-filled space were also installed to increase insulation efficiency and reduce heat transfer.
  • Several strategies were employed to maximize use of natural light and minimize energy needs for lighting including occupancy sensors that automatically turn lights on or off; solar tubes that transport natural light from roof skylights into interior spaces; sloped ceilings for optimal natural light reflection and retention and other daylight harvesting techniques that allow daylight to penetrate deep into classrooms.

By employing life cycle cost analysis and energy modeling throughout the design phase of the project, SHP was able to demonstrate that these innovative strategies could be incorporated into the campus with a modest 3% increase in the initial budget—all with the realistic expectation that the initial extra costs would be recaptured in the long term through enhanced energy efficiency.