More than 90,000 board feet of wood was harvested from the 1,500-acre Leopold Memorial Reserve and transformed into structural timbers, doors, windows, and artisan-crafted furniture throughout the facility, including the administrative square, three-season hall, conference center, and exhibit hall. While it seems that thinning the reserve would go against Aldo Leopold’s beliefs in acting ethically for the benefit of the land, the harvesting also benefited the reserve, which was suffering from overcrowding.
Fifty years ago, Aldo Leopold’s book “Land Ethic” put forth the idea that ethical human behavior includes acting responsibly for the benefit of the land, including soils, water, plants, and animals. In examining the connection between behavior and an ecological conscience, Leopold’s tome is regarded as a key component in the genesis of the modern conservation movement.
While Leopold died in 1948 (the year before “Land Ethic” hit shelves), his work continues on the site of the Aldo family farm northeast of Baraboo, Wisc., under the Aldo Leopold Foundation. It was only fitting, then, that when the foundation sought to create a visitor center, the 12,000-square-foot Leopold Legacy Center would be a model in environmental stewardship.
What would not work, recalls Wayne Reckard, marketing director at the project’s architecture firm, The Kubala Washatko Architects (TKWA), was a run-of-the-mill visitor center. “It would have been a mistake to go in and create a signature building that is isolated from its surroundings,” he says. “Buddy Huffaker, the foundation’s director, said they didn’t want a typical visitor center that offers a high-volume, low-intensity experience where tour buses come in and people get out and take pictures but do not connect with site in a meaningful way. What Buddy and Nina [Leopold Bradley, Aldo Leopold’s daughter] envisioned was a low-volume, high-intensity experience that would help people come into greater contact with the land and get a deeper appreciation of the land ethic.”
A complex of structures anchored by a central courtyard, the Aldo Leopold Legacy Center, which is a winner in this year’s Evergreen Awards’ Ecommercial category, includes three buildings. Together, the main building, Seed Hall, and the Axe-in-Hand Workshop house office and meeting spaces, an interpretive exhibit hall, library, archive, workshop, and an outdoor three-season hall/classroom.
A 39-kWh solar photovoltaic array on the roofs produces more than 61,000 kWh of electricity annually. The roof design bounces natural light into the interiors, reducing the need for electric light, while the overhangs are constructed to shield sun in the summer and allow passive gain in the winter.
Pulling from the land on which it sits, the center is constructed with timber milled from the property’s 1,500-acre Leopold Memorial Reserve. Although it seems harvesting 90,000 board feet of wood from a reserve would be the antithesis of Leopold’s ethics, the opposite was true. Examining the site, the designers found that the reserve, originally planted by the Leopold family in the 1930s and ’40s, was suffering from overcrowding. A strategic thinning process not only would reduce the chance of catastrophic fire and insect damage, but also would provide an abundance of raw material with which to build. The site-harvested wood was milled on-site and reused in structural timbers, doors, windows, and artisan-crafted furniture, with TKWA working with the U.S. Forest Service to develop a structural truss system that could incorporate smaller diameter wood. Finish materials were processed at a family sawmill about 90 miles away.
Using local resources also addressed the goal of creating a carbon-neutral facility. At the time of construction, the center met Architecture 2030 Challenge goals and was designed to consume zero net energy. In fact, the plans called for it to produce more than 110 percent of its annual building energy needs and use 70 percent less energy than a median office building designed to code. To save energy, the heating and cooling systems on the site are separated by an underground earth tube system that significantly reduces the amount of air delivered to each building. The tubes are constructed of 24-inch-diameter cement pipes that run air through a filtering system in the basement where a UV lamp removes mold and bacteria from the air before it is circulated.
Long, narrow floor plates allow optimum natural ventilation and daylight, and the building overhangs are designed to shield sun in the summer and allow passive gain in the winter. Geothermal radiant heating and cooling also contribute to mechanical efficiency, while a 39-kWh solar PV system produces more than 61,000 kWh of electricity annually. In addition, the roof is designed to bounce indirect natural light into the interior, reducing the need for electric lighting, and water is preheated by a roof-mounted evacuated tube solar array.
Energy use was a specific focus for the center, which was designed to produce more than 110 percent of its annual energy needs. Program spaces are purposefully disconnected from the main building to reduce energy loads.
At the time of its opening in spring 2007, the center was not only certified as LEED Platinum, but it was the highest-rated building measured under the LEED system. In the two years since, it has continued to perform well with a few modifications. For instance, although the team sought a net-zero building, it is not yet performing at that level. The amount of energy coming from the grid is under 10,000 BTUs per square foot, and the design team is working to reduce that to zero within the next year or two. “The plug loads were much larger than estimated,” notes Michael Utzinger, an associate professor of architecture at the University of Wisconsin, Milwaukee, who assisted with the project and continues to analyze data from post-occupancy evaluations. Original estimates predicted 7,000 kWh per year plug loads, but post-occupancy studies revealed first year totals of 17,000 kWh. There are a number of factors that played into this uptick, Utzinger explains, including the installation of several large-screen LCD displays and IT management practices that had employees leaving their computers on overnight for system maintenance. The project team discussed options with the foundation’s IT department to devise a way to shut down the machines overnight, reducing the electrical demand.
Recognizing the impact of end-user behavior on the building’s performance, the design team has met with foundation employees at the end of each year to discuss performance metrics. “We’re returning to the building with a sense of how it is used and understanding the different pieces that come into play,” Utzinger says. “One of the great unknowns is how people will occupy a building.”
For example, while plug loads were above estimates, lighting electricity use was much lower than anticipated, averaging 7,000 kWh per year. In comparison, Utzinger estimates that an average building that has its lights on while occupied would use about 22,000 kWh per year. “It turns out that smart occupants can do a very good job in reducing lighting energy,” he says, noting that the center has standard switches, not automated daylight controls, that leave the lighting levels at the staff’s discretion. The windows also are under staff control. While the control system will inform occupants whether exterior conditions are appropriate for natural ventilation, it is up to the staff to decide whether to turn off the mechanical ventilation systems.
Located on the Leopold family’s Sands County farm, the 12,000-square-foot Leopold Legacy Center is organized as a cluster of low-profile buildings around a central courtyard to maximize daylight and natural ventilation.
Another decision tied to building performance was the idea to organize employee offices in pairs, grouping those with similar temperature preferences on the same coil set within the radiant floors. The benefits of designing the flooring with smaller coil loops is twofold: water does not have to travel back and forth across the entire floor to heat the space, and it also helps employees feel more comfortable in their individual offices, increasingly their overall satisfaction.
Foundation employees aren’t the only ones satisfied with the center's day-to-day operations. Given the dedication to improving the structure’s performance going forward, including further reducing its impact on the land, Leopold himself would be pleased.
Rainwater is collected from the roofs and water for the buildings is preheated by a roof-mounted evacuated tube solar array.
Materials and Sources
Structural insulated panels: R-Control, r-control.com
Roofing: Standing-seam metal Galvalume Plus by AEP Span, aep-span.com
Photovoltaic panels: 198 (KC200 GT) panel by Kyocera, kyocerasolar.com
Solar inverters: Aurora PVI-3600 by Magnetek, magnetek.com
Wood finish: Water-based crystalline urethane by Timber ProUV, timberprocoatings.com
Paint: Eco Spec by Pittsburgh Paints, pittsburghpaints.com
Metal paint: Safecoat by AFM, afmsafecoat.com
Wood floor finish: Water-based finish Eon 70 by BonaKemi USA, bona.com
Cellulose insulation: Weather Blanket by Champion Insulation, championinsulation.com
Concrete floor stain: Acid etch with water-based sealer by Floor-Shield, floor-shield.com
Domestic solar hot water: JSP10 evacuated tube collector by BTF Solar, btfsolar.com
Wallcoverings: Homasote by Homasote Co, homasote.com; Skyblend particleboard by Roseburg Forest Products Co., rfpco.com
Radiant floors: Water-to-water pumps by FHP Manufacturing, fhp-mfg.com
Earth tubes: Concrete pipes by County Materials Corp., countymaterials.com
Insulated windows: Pella, pella.com
Aldo Leopold lumber: Custom wood windows by H Window, hwindow.com; custom wood doors and custom wood casework by Wallenfang Custom Millwork; custom wood siding and custom wood flooring by Samsel’s Sawmill, samselsawmill.com; timber framing and round wood trusses by Bachmann Construction, bachmannconstruction.net
Reused timber beams: Glenville Timberwrights, glenvilletimberwrights.com
Reused stone veneer: Dane County Airport Hanger
Plumbing fixtures: Toilets, waterless urinals, and low-flow fixtures by Kohler, kohler.com
Architect: The Kubala Washatko Architects,tkwa.com
General contractor: Boldt Construction Co., theboldtcompany.com
Commissioning agent: Supersymmetry USA
Energy modeling: Thermal Energy System Specialists, tess-inc.com
Enviornmental coordination: Helios Design
MEP engineer: Matrix Mechanical Solutions, matrixmech.com
Electrical engineer: Powrtek Engineering, powrtek.com
Structural engineer: Komp/Gilomen Engineering
Landscape architect: Misa Inoue and Marcy Huffake, Aldo Leopold Foundation, aldo.leopold.com
LED consultant: Theresa Lehman, Boldt Construction Co.
Photographs: Mark F. Heffron/TKWA