"Since 1978, the Center for Neighborhood Technology (CNT) has worked to show urban communities locally and all across the country how to develop more sustainably. With smarts, creativity and innovation, and before the term sustainable development was even widely used, CNT has been demonstrating its unique brand of sustainable development: development that is good for the economy and the environment; makes better use of existing resources and community assets; and improves the health of natural systems and the wealth of people—today and in the future."

Pairing such an organization with a building at the cutting edge of sustainability is a natural combination. Re-use of an existing building, rather than building a new facility is an excellent sustainable step, and a vital element in this green project.

Image Source: Center for Neighborhood TechnologyThe CNT building website offers an excellent overview of the number of steps taken to get the building LEED certified. The Green Building Renovation Virtual Tour highlights sustainable features in six categories: Site, Energy, Water, Materials, Light & Air, and Innovation. The building has many of the usual and familiar steps in green building: renewable carpet, salvaged material use, and construction waste recycling, large skylights, operable windows, low VOC finishes, low-flow fixtures, efficient appliances, and rooftop photovoltaic solar panels.
Image Credit: Center for Neighborhood Technology
Some of the more uncommon features include a "cooling garden" with trees to shade the building and reduce the need for summertime cooling. The building also has a minimum number of parking spaces (and a permeable surface parking lot) and abundant bicycle storage space and shower facilities to encourage bike commuters.

Photo Credit: Center for Neighborhood TechnologyAn ice ball thermal storage system is probably the most radical and interesting ideas in the building. The insulated tank (pictured, before installation) is buried underground next to the building. "In an underground tank, water-filled balls are frozen at night, using off-peak, lower cost energy. During higher-cost hours, a food-grade, glycol-based fluid transfers the chill from the ice balls to the building's cooling system." Because of the increased energy loads in office spaces as compared to single-family homes, in many cases cooling is needed much more than heating. Making ice during off-peak hours to be able to run the cooling system when it is needed during the day is a great way to use energy more efficiently. Burying the tank in the ground is an excellent step to further improve its efficiency by taking advantage of the steady earth temperatures which are found underground.

Building Information:
Location: Chicago IL
Architect: Jonathan Boyer (Farr Associates)
LEED-NC 2.0 Commercial Office, Platinum Rating

Links:
Center for Neighborhood Technology
CNT Virtual Tour

via: GreenBean