By OnMilwaukee Staff Writers   Published Aug 12, 2013 at 12:01 PM Photography: Royal Brevvaxling

Rockwell Automation has earned Leadership in Energy and Environmental Design (LEED) certification granted by the U.S. Green Building Council.

The certification comes after a 12-year effort to make its 2.1 million square-foot corporation headquarters at 1201 S. 2nd St. more environmentally sustainable. Rockwell Automation invested $3.2 million in upgrading the building, which is now the second-largest building in Wisconsin to receive such certification.

"The sheer size of the existing buildings was the most challenging – and rewarding – aspect of the program," said Steve Strzok, Rockwell Automation facility manager.

"Every part of the space had to meet LEED specifications for an operations and maintenance rating - including indoor air-quality standards, and ‘green cleaning’ procedures and products used by custodians."

Among the many improvements made to the headquarters, the most noticeable is the installation of of a "green roof" – the largest private-sector roof in Wisconsin, which reduces the energy required to heat and cool the building. It retains 1.2 million gallons of rainwater annually that would otherwise runoff into the city's sewer system and Lake Michigan.