I don't believe XIN would get building permits before they got financing nailed down. Financing is now nailed down...so permits should appear in the near future.
I don't believe XIN would pre-sell to the Chinese without construction started...since the Chinese appear to want to see updated construction photos every month or so. These construction photos are on XIN's Chinese web site....and I expect to see monthly updates of Williamsburg construction monthly. The latest information is that pre-sales might start in June.
Since XIN could not know if their Dollar bond deal would ever go through...they might have given Fall as a construction start time to give themselves time for other financing arrangements....such as the limited partner financing scheme.