3 world trade center was originally planned for a podium of seven stories for trading floors, with a 73-floor office tower rising from it. the diamond braces initially planned for the front and rear faces of the building have been dropped from the design and the tower is to be built without them. however, the diagonal bracing on the sides would remain. the four spires in the original design gave the tower a pinnacle height of 1,240 feet (378 m), meaning it would have become the third-tallest building in new york city by pinnacle height, but the spires were later removed from the design, thus reducing the height by about 88 feet (approximately 26.8 m). the total floor space of the building is planned to include of office and retail space. the building's groundbreaking took place in january 2008, and at that time it was scheduled to be completed by 2014. unusual for a high-rise, the building's concrete core would be built before the rest of the structure was completed. the structural engineer for the building was wsp. pritzker prize-winning architect richard rogers, of rogers stirk harbour + partners, was awarded the contract to design the building.