Apple’s Campus 2, the company’s currently in-progress corporate campus, has seen its costs swell to nearly $5 billion, according to Bloomberg Businessweek. Budgeted for less than $3 billion in 2011, the building’s estimated cost now exceeds the amount being spent on the new World Trade Center complex in New York, as the article notes for purposes of comparison. Located in Cupertino, California, the four-story ring “spaceship” building will take up 2.8 million square feet within 176 acres of trees, with roads and parking mostly hidden away underground. In addition to the size and the scope of the project, details such as 40-foot panes of concave glass from Germany and specially fabricated ceilings are contributing to the high budget. When Campus 2 is completed, Apple events are likely to be held at an on-site auditorium, without the need to use space in San Francisco. The move-in date is now set for 2016, Apple CEO Tim Cook announced in February, a delay from 2015. Apple declined to comment on the report.