The architecture of Hidden Oaks Nature Center mimics its natural surroundings. The facility is nestled between two large oak trees. Half of the building is conical-shaped to match the rising trunks of the oak trees, and the ‘skin’ of this cone is veneered with locally quarried limestone that resembles rough, furrowed tree bark. The other half of the building has the appearance of a treehouse; when visitors walk from the second floor onto the roof terrace, they find themselves under the canopy of the two flanking red oaks. The steel railings around this terrace are shaped in the form of abstract tree branches. Trees that were harvested during preparation of the site for construction were incorporated back into the building as exterior structural elements that support the roof’s overhang, interior columns within the entry lobby, or as stair treads, table tops, doors, and trim.
As a certified LEED-NC Platinum project, the Hidden Oaks Nature Center is located on a heavily wooded, 17-acre site, and includes a green roof, constructed wetlands for black-water cleansing, permeable parking surfaces, day-lighting, and sustainable materials.
With an abundance of natural daylight and direct views to the outdoors, we designed the nature center to be a healthy, engaging, and environmentally friendly place for employees, students, and visitors. The building incorporates:
- Site-harvested timber
- Recycled and locally available materials
- Light shelves for daylight harvesting
- Low-flush toilet fixtures and urinals
- Solar-powered, motion-sensored faucets.
We strategically placed sunshades to minimize glare and solar heat gain. Paints and varnishes which contain no or low VOC levels, and wood products that do not contain added urea-formaldehyde heighten the quality of indoor air. Photovoltaic panels, connected in parallel to the electrical service, supply the building with energy, while excess output returns back to the grid. In addition, occupancy sensors turn off interior lights when staff or visitors are not present.
Sustainable strategies continue on the exterior, including integrated photocell and time clock devices that control site lighting. The green roof features native plants that do not require irrigation. Permeable pavers in the entry drive reduce stormwater run-off while also minimizing urban heat island effect. A geothermal system provides an efficient way to heat the building during winter and cool it during summer, while Energy Recovery Ventilators reduce energy by reusing pre-conditioned air.
Since the nature center is built in a restored oak savannah ecosystem, the placement of the building to minimize disruption of the site was critical. Trees that had to be removed from the site were harvested and repurposed for uses inside and outside the building. The trees also inspired the design of the building. From the “tree stump” circular form of the main building to the use of local materials, the building blends into its surroundings. The vegetative roof, permeable paver driveway, constructed wetland, and photovoltaic panels also support the building’s mission to be energy efficiency and environmentally sustainable. A pedestrian/bike trail system links the nature center to other nearby park facilities and the community.
An innovative design feature at Hidden Oaks is its constructed wetland. The most unusual aspect of this wetland is the source of its water—the facility’s restrooms. All of the center’s liquid sewage is cleansed by passing it through rocks and plants in a self-contained wetland cell, which is a natural treatment system for black-water. Microbes and aerobic activity in the cell act as a bio-filter to remove sediments and pollutants such as heavy metals. The result is a final discharge of water through a drip irrigation field that is clean, or cleaner, than a conventional wastewater treatment plant’s outflow.
- 2012 Frank Lloyd Wright Honor Award, AIA Illinois
- 2010 National Design-Build Awards, Design-Build $10 Million & Under, Design-Build Institute of America
- 2010 Impact on Learning Award - High Performance Schools, School Planning & Management
- 2010 Merit Award, New Construction Under $10 Million, Chicago Building Congress
- 2010 Honor Award, American Council of Engineering Companies of Illinois
- 2009 Merit Award, Green Building, Midwest Construction