Through a special interview with Daniel Radcliffe he said that filming would take place at Leavesden, but anyway, read on…
HP: Last time we spoke you mentioned you had never watched Star Wars.
HP: Well, except for The Phantom Menace.
DR: Let’s not tell anyone that.HP: You have to catch up before “Episode VII” comes out.
DR: I know! I know I do. I have to catch up before that because all of my friends are working on the new one. Because “Star Wars” is filming in Leavesden. There was at least one guy, Digby Milner, who worked on all the “Potters” who had also worked on “Star Wars,” the originals. And he will be working on new “Star Wars” at Leavesden as well. And it is kind of amazing because “Star Wars,” the originals, were made in England as well. So there’s a lot of that crew who we’ll basically have a huge amount of sons and daughters of the original crew who are now on the new “Star Wars” movie.
HP: It’s come full circle.
DR: That’s all they do at Leavesden, apparently, is franchises [laughs]
Source: Jedi News