After the 9/11 terrorist attacks in New York, many people wondered if the World Trade Center would be rebuilt. We discussed this and other issues in a short policy paper discussng the future of cities.
The Twin Towers comprised 9.5 million square feet of office space. The entire WTC complex consisted of about 30 million square feet, and about 13 million (40 percent) were destroyed in the attacks. At the time, we noted Manhattan already had a surplus of office space, and that the market would unlikely replace it all unless there were significant subsidies.
Well, the newest proposal for rebuilding on the site proposes a complex of six office towers. Even with space dedicated to parks and a memorial, the new buildings will add 12.3 million square feet of new, class A office space. The new complex is expected (now) to cost about $6.6 billion. The complex will be funded using $4.6 billion from the insuance policy and $3.5 billion in "liberty bonds". The liberty bonds are tax exempt bonds issued by the city, and their allocation is controlled by the city of New York through its development agencies.
More information on the World Trade Center rebuilding project can be found here.