Tulliallan: Is there a cost for retainer wall?

We have just gotten settlement for our land in stage 15B at Tulliallan estate yesterday. We seem to have a retainer wall at the back. Does this bring in additional building costs?

Hi, congratulations on your settlement!
If the retainer wall is already there, it should have any additional building costs provided your land is compacted. I'm building in a stockland estate and I've been advised from the builder that as long as We get a compaction certificate from stockland, we shouldn't need piers.
Once your soil testing and contour survey come back, your builder should be able to tell you if any additional costs are involved
Good luck