Dignitaries broke ground on the project Thursday.
As part of the celebration, construction crews will remove some of the blue panels from the exterior of the building to be signed. They'll go on display at the airport.
RDU officials said the $68 million makeover will include more natural lighting with larger ticketing, security checkpoint, and bag claim areas.
The plan also includes new restaurants and shops and works of art.
Workers finished the second phase of the new Terminal 2 in January 2011.