by the beginning of 2012, silverstein properties and the port authority of new york and new jersey reached an agreement to only build 3 world trade center to seven stories, unless tenants can be found to fund the building. according to a march 2010 agreement between silverstein properties and the port authority, silverstein properties must find tenants to lease 400,000 square feet of the building and it must raise in private financing in order to receive additional funding. if silverstein properties meets those triggers, then the port authority, city of new york, and new york state will provide an additional towards the tower's completion. silverstein properties also needs to provide financing for the remaining cost of the tower before it can be completed. the existing foundation of the tower was built entirely with insurance proceeds, and until silverstein properties meets the requirements. the agreement also implemented a "cash trap" to make sure that public investments are paid off before silverstein properties makes any profits from the tower.