Rapid, haha. I hear the plan from the developer is to build 200 homes a year, starting with the (obviously more desirable and easier) green fields and eventually moving on to the MOD land later - much later.
If it was really being built at say 2000 houses/year then it might help the local housing shortage, but trickling them out at 200/ year is just profiting from high house prices over a long time without materially relieving the housing shortage.