The John Dorr Nature Laboratory is located in the greenest corner of western Connecticut. Tucked into the foothills of the Berkshires, it serves as an environmental campus for elementary through high school students who attend the Bronx-based Horace Mann School.

The school had ambitions of becoming as green as its bucolic surroundings -- and using its new energy-conserving facilities as part of its curriculum. So Horace Mann officials engaged Centerbrook Architects, a firm that has been designing sustainable buildings since the 1970s. Jim Childress, one of four Centerbrook partners, and project manager Sherri Dieso met with school officials and students to assess their needs and visions for an upgraded and expanded satellite campus. 

Circle meetings take place in the rug room on a daily basis at John Dorr. Clerestory windows and ceiling fans aid the natural ventilation on warm days, while radiant flooring and roaring fires provide added comfort on cold days. Photo credit: Roger Williams, Centerbrook Architects

The John Dorr Nature Laboratory, set on 265 diverse acres, provides a wide array of programs. Starting in second grade, students participate in year-round programs such as afternoon field trips and eight-day explorations -- each designed to increase student awareness, understanding and appreciation of the natural world. The new 17,000-square-foot facility was designed to exemplify a commitment to environmental responsibility and stewardship.

The two-part building includes a lodge and adjoining classroom building, or “barn,” which is supported by the existing girls and boys bunkhouses; two on-campus faculty houses; and the existing lodge. Serving as the gathering space for students and faculty, the new lodge building comprises a comfortable lounge and dining area, a “rug room” for meetings, a combined game and conference room, a commercial kitchen, administrative offices, shower rooms for overnight programs, and an equipment room to store all necessities related to hiking, camping and outdoor exploration.

The barn’s 24-foot-wide folding door allows the exterior to become an extension of the classroom. Photo credit: Roger Williams, Centerbrook Architects

The adjacent barn houses a classroom that opens to the exterior with a 24-foot-wide folding door, a wet lab, and two faculty apartments. The siting of the lodge building reflects the need to be in close proximity to the bunkhouses that the shower rooms serve and to take advantage of the existing contours and maximum solar access. 

Since its inception, the goal for this project has been to achieve LEED Gold and to build a home for John Dorr Nature Laboratory that is, in itself, an educational tool. Horace Mann officials insisted on the implementation of renewable energy, water conservation and wastewater reduction, rainwater harvesting, maximum energy efficiency, natural ventilation, and loads of daylight. The new building has an energy savings of 38 percent as compared with a similar conventional building.

Evacuated-tube solar collectors generate 90 percent of hot water for domestic use; the photovoltaic arrays provide 30 percent of the building’s power needs. Flues extend from two interior fireplaces that provide immeasurable warmth and comfort. Photos credit: Roger Williams, Centerbrook Architects

The lodge building and barn are oriented to take advantage of solar gain for daylighting within the building and to provide maximum solar access for photovoltaic arrays and solar collectors for the generation of power and domestic hot water. The 32 kilowatt photovoltaic array, which received an incentive from the Connecticut Clean Energy Fund for half of its installed value, is mounted on the sloped, south-facing lodge building roof and provides more than 30 percent of its and the barn’s power needs. The southeast-facing barn roof is wired for a future array that will increase power generation to 50 percent of the building’s requirements, assuming the same efficiency panel is installed.  The solar thermal collectors are designed to heat 90 percent of the required hot water for domestic use, and its glycol system incorporates a cost-effective, environmentally friendly transfer solution made from corn, which is 100 percent renewable, bio-degradable and has no petroleum content.

Designed to be high performing, the building’s envelope uses Icynene spray insulation with an R-value of 3.6 per inch: R-19 at walls and R-36 at the roof. Both the lodge and barn have proven to be very tightly constructed. Their interior and exterior materials incorporate those that are environmentally responsible, sustainable or minimally used (e.g., exposed structure in lieu of ceilings, polished concrete with no additional floor covering).  

Except at administrative areas, natural ventilation replaces the need for air conditioning by using operable windows, ceiling fans and motorized clerestory windows. A donor provided funding for a DX Exchange Geothermal System to cool the offices and conference room; the rug room, which acts as a plenum for the system, becomes the beneficiary of “free” air conditioning.

In addition to scholastic activities, concerts are performed inside and under the porch while audiences are ensconced in the “boulder amphitheater” and lawn outside. Photo credit: Roger Williams, Centerbrook Architects

Water efficiency is maximized in the building with the use of low-flow plumbing fixtures, timed showers, waterless urinals, and rainwater harvesting for toilet flushing, with a water savings of 38 percent and wastewater reduction of 53 percent. Excess rainwater is sent to the buried cistern for use in lawn care and the hosing down of muddy boots, etc. Overflow is directed to a rainwater garden downhill.

These new energy-conserving facilities opened this past fall at the John Dorr Nature Laboratory, which is in its 45th year of operation offering programs such as water explorations, astronomy, habitat exploration, entomology, and climbing a 45-foot adventure tower and rope course.

The new buildings are expected to save nearly 40 percent of the energy a comparable, conventionally built structures would consume, saving an estimated 4,120 gallons of propane, or 110,645 kilowatts of electricity, and reducing carbon dioxide emissions by as much as 42 MT (metric tons) annually.  These energy-conserving features are expected to save the school about $10,000 annually in utility costs. “Horace Mann is proud of its efforts to teach students and faculty alike about the importance of minimizing the school’s carbon footprint,” says Dr. Thomas M. Kelly, head of school for Horace Mann.