Before Arkham Asylum Incident
During the defeat of the Joker In Arkham Asylum, Bruce Wayne began working on the project much before the starting of Arkham Asylum. While Batman was in Gotham with Alfred, he began working on it.
Before Arkham Knight Incident
The project began after both The Joker's death and the closing of Arkham City. Bruce Wayne wanted to use North Gotham and re-connect it to Gotham City. So Bruce gathered some of the finest minds to help him reconstruct the former prison into a new and refreshing place to live and start businesses. Wayne also has plans to reinvigorate the rest of Gotham City as well. Introducing changes such as making Police Commissioner Gordon the new mayor. Bruce Wayne hopes others will donate to help his project along and give Gotham a brighter future.
Arkham Knight Incident
After Arkham Knight Incident
It is unknown what happened to the project after the "death" of Bruce Wayne, but if it the plan wasn't terminated, Lucius Fox is presumably leading it as he now owns Wayne Industries.