The study also showed that additional costs associated with green construction varied across projects, with a median value of $3.81 per square foot. In addition, building occupants are generally satisfied with their work environment and the commute to these LEED® projects.
 

“Not all green buildings are alike when it comes to energy efficiency,” said Anne Evens, director of the nonprofit CNT Energy, which conducted the study in partnership with the U.S. Green Building Council – Illinois Chapter (USGBC – Illinois). “Maximizing efficiency requires starting with the right priorities, monitoring usage, and tweaking operations and maintenance over the life of a building. Buildings account for a large portion of our global warming emissions here in Chicago, and building owners need to be diligent about efficiency to reduce emissions and save on utility bills.”

The study, “Regional Green Building Case Study: Year Two Report,” is a follow-up to a 2009 study that examined the energy usage and other environmental factors in 25 LEED-certified buildings in Illinois. Of the 51 buildings in this report, 19 also participated in 2009. To receive LEED (Leadership in Energy and Environmental Design) certification, the U.S. Green Building Council rates green building projects on a point system for features that improve energy efficiency, indoor air quality, water use, and other areas. CNT Energy analyzed how projects performed over multiple years in areas including energy and water use, greenhouse gas emissions, operating costs, commute transportation and occupant comfort.

The participating green building projects include offices, museums, police stations and other building use types. The study’s sample represents nearly 25 percent of the state’s LEED-certified projects and includes projects from throughout the Chicago metropolitan area and central Illinois.

The projects vary in size from 971 square feet to 4.2 million square feet. All provided at least 12 months of post-occupancy energy utility data. Most were able to provide energy use information for entire buildings, while 16 were able to provide only partial information about energy usage.

According to the U.S. Energy Information Agency, the average energy use intensity (EUI) for commercial buildings in the Midwest is 99 kilo-Btu per square feet per year (kBtu/ft2/year). Sixty-four percent of the LEED projects that provided energy use data for the entire building used less energy than this average for commercial buildings. Likewise, 77 percent of projects that provided partial energy use data performed better than a similar benchmark.

For full report visit: http://www.usgbc-illinois.org/?page_id=2905

The U.S. Green Building Council – Illinois Chapter is Illinois’ only nonprofit organization focused solely on green building and community design, construction, and operation. The mission of USGBC – Illinois is to transform the region’s built environment to become ecologically sustainable, profitable, and healthy. We accomplish this through education, advocacy, and collaboration. As Illinois’ green building advocate and education resource, USGBC – Illinois provides over 150 educational programs, events, green building tours, research studies, and advocacy initiatives each year, through its seven-branch, state-wide network. The nearly 1,600 members of USGBC – Illinois represent the entire spectrum of the Illinois green building community.

USGBC – Illinois serves the state through its seven regional branches: Central Illinois, Chicago, Fox Valley, North/Northwest Suburban, Rockford/Northern Illinois, South Suburban, and West
Suburban. The work of USGBC – Illinois falls into four key areas of focus: Green Buildings and
Sustainable Communities, Green and Healthy Schools, Green and Affordable Homes, and Jobs
for the Green Economy.

For more information, go to www.usgbc-illinois.org.