Blue Ridge Parkway Destination Center targets a LEED Gold certification level, featuring a passive solar Trombe wall systems that intends to contribute to a perfect score of 10 points in the Energy Optimization category. © Jonathan Hillyer / Atlanta.

On a hillside in the Great Smoky Mountains National Park, trees felled for the construction of a new research center were either left on site to provide habitat or mulched and spread to prevent erosion. Rocks and boulders displaced by excavation for the facility were salvaged for retaining walls and to form natural stormwater management features. In the Blue Ridge Mountains of North Carolina, an extensive green roof caps the new visitor destination center, providing habitat, while passive solar Trombe walls harvest natural solar energy to heat the facility.

These two recently completed facilities in the southeastern United States embody the National Park Service’s (NPS) commitment to sustainable design.

The National Park Service Mission and Call to Action

“The very nature of the environment appears to be changing greatly because of the interactive effects of cars, coal, nuclear power, exploitation of forestry, destruction of habitat, global warming, and other factors. Basic human needs are not being met… Most modern architecture, transportation, and food production was created on, and is dependent on, the assumption that using fossil fuels for energy is economical and that their supply is inexhaustible… How can more acceptable relationships with the world be developed?”

Photo courtesy of Lord, Aeck & Sargent.

I first read this call to action in the NPS Guiding Principals of Sustainable Design as an architecture student in the fall of 1993.

The NPS mission is to preserve the natural and cultural resources and values of the national park system “for the enjoyment, education, and inspiration of this and future generations.” Guided by a mission explicitly embracing sustainability—meeting the needs of this and future generations—it is not surprising that this federal government organization was an early champion of sustainable design.

Guiding Principals of Sustainable Design highlighted the risks posed by human activities, and provided a basis “for achieving sustainability in facility planning and design,” emphasizing the importance of biodiversity and encouraging responsible decisions. It recognized the transformative potential of sustainable design, calling for visitor experiences to be “planned to provide actual knowledge of resources and to influence human values, thus leading to the protection of the overall environment.”

Both Blue Ridge Parkway (shown) and Twin Creeks embody the National Park Service’s commitment to sustainable design.© Jonathan Hillyer / Atlanta.

Twin Creeks Science and Education Center

The Great Smoky Mountains National Park’s new Twin Creeks Science and Education Center, located outside of Gatlinburg, Tenn., was designed to study and protect the park’s ecosystems, including the adjacent trout streams for which the building was named. Providing offices for researchers as well as space for laboratory work, educational instruction and flexible workstations, the 15,000-square-foot facility dramatically improves the park’s facilities for research, inventory and educational activities and helps the park fulfill its mandate to protect and preserve these important resources for this and future generations. Researchers at Twin Creeks are undertaking an All Taxa Biodiversity Inventory (ATBI) to identify and catalog all living species within the park. This facility will provide the needed curatorial space to house the growing natural history collection resulting from the ATBI effort. The facility opened in October 2007 and is pursuing LEED Silver level certification.

The project honors the NPS’s strong commitment to sustainable design, incorporating a number of high-performance and green design strategies. Parking was minimized and constructed with pervious materials, and the barrier free entrance trail was formed with a mix using recycled slag and aggregate concrete. Runoff from the roof is collected and processed through a series of cascading natural stormwater management features. These include roof drains routed to a planter zone, which overflows via scuppers to vegetated swales, which then feed into a series of three interconnected water quality ponds.

Image courtesy of Lord, Aeck & Sargent.

It was necessary to excavate a large amount of loose rock and boulders from the building site. In order to reduce construction waste, several planned concrete retaining walls were eliminated from the project, and rubble retaining walls were instead formed with the removed rocks. This reduced waste and the amount of concrete required on the project. The rocks were also used to form the water quality ponds and swales.

A high-performance building envelope, including Structural Insulated Panels, extensive use of daylighting throughout with automatic daylight-harvesting controls in the multi-occupancy spaces, occupancy sensors in all offices and corridors, and a natural ventilation system with automatic controls all help reduce the facility’s reliance on fossil fuels.

The NPS is “highly interested in using tools such as LEED to help design and construct buildings that use less embodied energy to build, and less energy and cost to operate and to maintain,” says Deborah Rehn, AIA, project manager from the Southeast Regional office of the NPS. “Without the LEED rating system to help guide in the design process and to maintain course during construction, it would have been much more difficult to incorporate many of the ‘green’ features that we have in the building.”

Image courtesy of Lord, Aeck & Sargent.

Blue Ridge Parkway Destination Center

Located adjacent to the Blue Ridge Parkway headquarters near Asheville, N.C., the recently opened Blue Ridge Parkway Destination Center was designed to orient visitors to the history, culture and resources of the parkway and surrounding region, while serving as an exhibit of sustainable, environmentally responsible architecture. The 12,000-square-foot center features a host of sustainable design strategies, among them an innovative, computational fluid dynamics (CFD)-optimized passive solar Trombe wall system, which contribute to the project’s projected “perfect score” of 10 LEED points for Energy Optimization and LEED Gold Level targeted certification level[1].

Lord, Aeck & Sargent’s architects collaborated with CFD modelers from Pennsylvania State University’s Applied Research Laboratory to design the Trombe walls.

© Jonathan Hillyer / Atlanta.

A high-efficiency HVAC system uses an energy recovery unit to transfer heat from air exhausted out of the building to air entering the building in the winter. In the summer, the energy recovery unit pulls moisture out of the air that enters the building. This technology will result in significant energy use reduction throughout the life of the building. A hydronic radiant heated floor system provides heat to supplement the passive solar system. Operable windows allow for natural ventilation in the offices and exhibit hall.

Photo sensors turn on the artificial lighting for general illumination only when daylight levels are insufficient to light the building, and occupancy sensors ensure lights are turned off when occupants leave.

The facility is capped with a 10,000-square-foot green roof, 100 percent of which is planted with native, drought tolerant plants. The green roof helps to treat and retain stormwater runoff. A pair of in-ground cisterns capture rainwater for use on site, and runoff from the parking lots is channeled into a bioswale from which it is then filtered and seeps into the groundwater. For more information on this facility, see the full story in ED+C’s May 2008 issue.

These two new green facilities provide a physical testament to the National Park Service’s long-standing commitment to sustainable design.

1. At press time, the project has completed the first round of the USGBC’s LEED Technical Review, with all 10 Energy Optimization Points plus one Innovation Point for Exemplary Energy Optimization accepted.



Resource

Guiding Principles of Sustainable Design:

www.nps.gov/dsc/dsgncnstr/gpsd/toc.html