en.m.wikipedia.org
“Berg earned a bachelor's degree in architecture from
Iowa State University in 1997, and served on the design faculty there for three years.”
...
“(Berg) built another tower in the College of Design's atrium at
Iowa State University in 1998. It stood at approximately 25 feet (7.6 meters) tall and used over 1500
decks of standard cards weighing over 250 pounds (110 kilograms). It took two and a half weeks to build working in shifts from four to twelve hours each day. During construction, the tower was surrounded by
scaffolding.”