Wake County

Cause of cracked windows on state buildings in downtown Raleigh still unknown

The state is still awaiting the results of tests to determine why windows have begun to chip and crack on two new downtown state buildings, including the Nature Research Center of the N.C. Museum of Natural Sciences.

But in the month since scaffolding went up around the two buildings that make up the Green Square complex, cracks have developed in just one additional window, in a bridge across McDowell Street that connects the buildings, said Christopher Mears, spokesman for the state Department of Administration.

Out of about 5,000 panes on the two buildings, 17 have developed cracks or chips, Mears said.

State officials don’t think the cracks are related to the installation of the windows and are awaiting lab results on the glass itself. The windows were made with high-efficiency glass designed to minimize the amount of solar heat inside the buildings, which were completed in late 2011 and early 2012.

“This is such a special glass that there could be an issue with its manufacture,” Mears said.

Most of the chips of glass have fallen inside the buildings, Mears said. The scaffolding to protect sidewalks and barriers to keep people 15 feet away from the building went up as a precaution in advance of the museum’s BugFest on Sept. 20.