We've just found out (courtesy of dreamer_kerry via the Home One Forum - thank you Kerry) that we have a planning overlay on our land. On the map above, taken from the planning department website there's a thick blue line running along the top of the estate and then diagonally through the eastern end. I'm pretty sure this was originally a narrow agricultural run-off, as we had a slight ditch running through our land on this same angle.
Kerry is building with PD, and they have informed her that a special town planning permit must be applied for which will take around 3 months to come through. We've checked with our builder, Carlisle, and they don't believe it's going to be a hold up, but they'll get back to us later today or tomorrow with more info.
So basically, my reason for this post is to see if anyone else on the estate has been affected and to alert those who may be affected of the possibility of more delays. If anyone has encountered a similar issue and would like to share the results, I'm sure there'd be a few of us anxious to hear about it.