Jewish Reconstructionist Congregation
Repairing the World: A LEED-Platinum synagogue uses passive strategies to achieve greater-than-expected energy savings.
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Tikkun olam means “repairing the world” in Hebrew. Most often used to refer to doing something for the public good, it became the inspiration for the design of the synagogue for both the congregation and the project team, led by Ross Barney Architects, as they designed the LEED-Platinum building. The result, according to AIA Top Ten jury member Bill Leddy, FAIA, is “a beautiful, simple, elegant link between religious values and sustainable values.”
Having a client with such clear goals was useful, says Carol Ross Barney, FAIA. “It was beautiful to take on a project and to be able to guide it with a single principle.” With a limited budget, achieving LEED Platinum wasn’t easy. “We had to make sure we got the best technologies for the budget,” Ross Barney says. “It’s a very sensible building.”
Local ordinances limited the size of the building, which would sit on the same site as the smaller synagogue it replaced. Originally imagining a 42,000-square-foot building, the project team mapped hourly usage patterns and increased the flexibility of indoor spaces to arrive at the final 31,600-square-foot program. The result is a deceptively simple cube with spaces that can be used for many different purposes.
A smaller building had other benefits, both inside and out. Creating an electrical and plumbing core in the middle of the building pushed occupied spaces to the exterior walls, making both daylighting and passive ventilation easier. An open staircase along one side of the building provides an atrium where air can move from the ground floor up, exiting through an exhaust fan at the top of the staircase, promoting airflow. The stair also serves as a thermal buffer that moderates temperatures inside the building. Operable windows in the classrooms are located at the bottom and top of exterior walls, again promoting the upward flow of air. To augment these passive strategies, low-velocity displacement ventilation was used in the top-floor sanctuary. Elsewhere in the building, variable-air-volume devices have controls in each room so occupants can regulate ventilation rates.
High-performance glazing and walls with high insulation values (R-28) minimize heating and cooling loads. A high-efficiency (94-percent) gas-fired, condensing boiler provides heat and hot water, while an air-cooled, modular chiller with a 14-to-1 turndown ratio cools the space. A building automation system monitors the climate inside, indicating when natural ventilation will suffice; at those times heating and cooling systems turn off, and the windows in the staircase atrium open. Occupancy and daylight sensors control the lighting, enhancing energy efficiency.
According to Ross Barney, the building automation system allows them to keep a close eye on the building. “We are able to monitor small items that make a big difference in how the building operates,” she says. By observing each individual room, for example, the project team discovered a “short circuit” in the air-intake system that it was able to correct. The ongoing commissioning process has increased the performance of the building, which is using over 35 percent less energy than expected, despite increased members. The team attributes some of these unanticipated energy savings to a shortcoming in the energy simulation, which failed to account for the thermal buffer effect of the unconditioned stairwells just inside the glazed walls. But congregational involvement in managing energy use is no less important, says Ross Barney. A committee at the synagogue collects and reviews the performance data and continues to work with the project team to fine-tune the building.
Outside, the smaller size of the building allowed more room for stormwater management. Using pervious materials on 43 percent of the site allowed the team to reduce stormwater runoff by 25 percent. Underground cisterns collect rainwater and release it slowly into the ground to avoid overload. As part of their commitment to tikkun olam, members of the congregation saved existing plants, replanting them once the project was done. The rest of the landscape was planted with native and adapted species. Four maple trees from the site that could not be saved were milled and used for the building’s ceremonial entrance.
The project team wanted to stay away from complicated green strategies, and kept the building’s shape, circulation, and materials straightforward. This wasn’t always easy. According to Ross Barney, “The biggest challenge was making the building holistic and simple. It’s hard to be simple.”
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