Photo Gallery: The Tower at PNC Plaza

PNC Financial Services Group opened its nearly completed headquarters in Downtown Pittsburgh to the public on Thursday.

Called “the greenest office tower in the world,” the 33-story high rise at the corner of Fifth Avenue and Wood Street has the highest level of certification under the U.S. Green Building Council's Leadership in Energy and Environmental Design program.

The Tower at PNC Plaza incorporates technology to lower energy usage and naturally cool and heat the office space. A double-skin façade allows fresh air to enter and pass to the interior, and a “solar chimney” at the core of the tower allows warm air to rise throughout the building.

PNC officials said the two systems should allow for natural ventilation at least 42 percent of the year. Also, a water recycling and treatment system reuses and treats rain and wastewater for flushing, cooling and irrigation. PNC officials said the tower is 50 percent more energy efficient than standard buildings and saves 77 percent more water.

The Tower at PNC Plaza will host roughly 2,200 employees, who will gradually move there in the coming months.