Award Description

This two-story, 108,000 sq. ft. K-4 elementary school was built in response to increased enrollments at the elementary school level. The school opened for the 2009-2010 academic year, and features 44 classrooms, a cafeteria, gymnasium, library, computer labs, art and music classrooms for an estimated 700 students.

The $22.1 million school was designed by AEM Architects, Inc., which also designed the nearby Tilden Elementary Center in Hamburg, PA with CarbonCast High Performance Insulated Wall Panels. The Tilden school was completed in 2007.

Willow Creek was built in proximity to other Fleetwood facilities, and takes the place of an older block and brick structure. According to AEM project architect Justin H. Istenes, the insulated wall panels were chosen for the school because “precast is built to last. The owners toured High’s Denver plant and the Tilden school while it was under construction, and were satisfied they were getting better value with precast insulated wall panels.”

Three inches of rigid extruded polystyrene (XPS) foam sandwiched between the 3” exterior wythe and 4” interior wythe provide a composite R-value of 16. The wythes are connected by low thermal conductivity C-GRID™ carbon fiber shear trusses. “R-value isn’t a perfect indication of energy efficiency because of thermal bridging,” says Istenes. “These concrete mass walls provide continuous insulation because the wythe connectors minimize potential energy loss.”

“Traditional [building] methods require refreshing sooner,” says Istenes. “Voids and cracks of traditional block and brick make it less efficient over time.” Thermal performance of the precast facade is enhanced by a high-efficiency SouthWall glazing system with a Krypton-filled with a thin layer of HeatMirror film suspended between two air spaces to reflect the solar energy in the summer and absorb it in the winter. The glazing provides a u-value of .11 (R-value of 9). The project also included advanced HVAC controls for measurement and verification of system performance.

Though the project could have qualified for LEED or other green rating systems, the owner was interested in achieving the performance benefits of green building techniques without pursuing formal certifications.

The exterior loadbearing precast walls are fully structurally composite, meaning that the interior and exterior wythes act together to resist gravity, lateral and seismic forces. The design enabled the walls to be thinner than other systems, preserving usable floor space for occupants. The precast facade was panelized to 14’ widths to minimize the number of joints and to optimize shipping efficiency.

Interior walls are also precast which according to Istenes allowed the project to flow more smoothly during erection rather than having steel and block make up the structure on the building’s interior. Conduit for exterior lighting and fixtures was cast into the interior wythe of the panels for aesthetics and durability over time.

Back surfaces of the insulated panels were trowel-finished “… with a smoothness that almost looks like gypsum board,” says Istenes. This step eliminated drywall and the associated dust which would have required control and clean up. The walls were painted with off-white block paint and are the exposed surfaces of the classrooms and halls.

Project Participants

Owner - Fleetwood Area School Dist., Fleetwood, PA
Architect/Designer - AEM Architects, Reading, PA
Structural Engineers - Multani Associates Inc., Wyomissing, PA
General Contractor - Wohlsen Construction Co., Lancaster, PA
Concrete Contractor - High Concrete Group LLC, Denver, PA
Masonry Supplier - Glen-Gery, Wyomissing, PA