150 Greenwich Street is the address for a new skyscraper to be erected as part of the World Trade Center reconstruction in New York City. The office building has also been referred to as World Trade Center Tower 4 and will be on the east side of Greenwich Street, across the street from the original location of the twin towers that were destroyed during the September 11, 2001 attacks. Noted architect Fumihiko Maki was awarded the contract to design the building which will be 947 feet (288 m) tall, which will make it the fourth tallest skyscraper on the World Trade Center site. New revised plans state the tower will now rise a total of 975 feet (297 m). The total floor space of the building is anticipated to include 1.8 million square feet (167,000 square meter) of office and retail space. Excavation for the new building is expected to commence in 2007 and the building will be completed by 2011. The structural engineer for the building is Leslie E. Robertson Associates, New York City.