Thrivent Financial for Lutherans, a not-for-profit financial services organization with $6 billion in 2008 revenue, greatly reduced emissions and realized significant savings when it made changes to increase the energy efficiency of its 17-story corporate center in downtown Minneapolis. And while Thrivent was making those changes, grassroots interest among its employees led to the formation of committees that are taking on green projects.

In 2003, after the Environmental Protection Agency’s energy efficiency rating on the Minneapolis building came in at just 44%, lower than average for office buildings, Thrivent hired a consulting firm to identify ways to cut the building’s energy use and costs.

The changes it put in place range from installing a solar reflective roof; converting most heating, ventilating and air conditioning controls to direct digital control; modifying the building’s air ducts to reduce leakage; and switching to lower-watt lamps. Half the savings reflect a single project, Thrivent’s installation of two high-efficiency chillers to make its own chilled water to cool the building, instead of getting chilled water from a utility.

By 2007, the building’s rating had surged from 44% to 86%, winning it an EPA Energy Star award. The changes reduced the building’s greenhouse gas emissions by almost half and are saving Thrivent $600,000 a year. Thrivent is now working to increase the energy efficiency of its other office building, in Appleton, Wis.

“Some of the things we did sound minor in nature, but when you do them on a large scale, it’s amazing the results you can get,” says Kirsten Spreck, Thrivent’s director of corporate real estate.

Meanwhile, more than 70 employee volunteers on Thrivent’s Green Team are looking for environmentally friendly improvements in areas from commuting and facilities services to procurement, recycling and resource usage. Their initiatives range from donating expired food items to charity, rather than throwing them away, to increasing recycling and promoting local agriculture.