Hi!
There was a restriction that was placed on our land that we didn't know about & our DA had already been submitted - we are next to a pathway, so the council requested that we make a few changes to the side of our house to make it look more decorative & also asked us to put a drop edge beam in to reduce the amount of cut & fill. It took a while to get new plans with changes drawn up & resubmitted (Didn't help that this was over the xmas period) but once we relodged to council though only took just over a week & it was approved.
Definately a good idea to book an appointment with council before lodging your DA and they will sit with you and go over your plans & tell you of any problems that they see - wish we had of done this would have saved us a lot of time.
I think that we bought land off the same developer as you, are you near the Annfield Estate?
Your house sounds great! Such a good way to use the space
Hopefully you won't get held up in council - although you have plenty of time before your land is registered. Once you have signed off on your contract they will draw the plans up for council & then submit the DA so hopefully if there are any delays with council they will all be sorted before your land registers!