We commenced a small (hahaha) reno on our pre-1900s terrace in Sydney several weeks back. The block is a funny shape - rectangular, but ~3.5m at the front and ~4m at the rear. We are the end terrace on a row, with the neighbor on the 'open' end being Council. There is a dead space, and then a fence, between us and the councils usable land. Unfortunately, during demolition, the main side wall of the terrace was found to be structurally unsound, so after another round of approvals, we have demolished most of it, and built a new wall, simply with a string line from the retained section of wall at the front, to the original footing at the rear - both points 'within' our lot. Given that the original wall was completely on the **** (banana + 100mm (avg) lean), and that this wall was our boundary - what happens in the event our "new" wall is perfectly straight and therefore over the original boundary ? - if that makes sense? As we never intended for the wall to come down, and only a relatively small section of the 'boundary' was affected, we overlooked getting a survey peg done, given the fact 'its just a straight line'. I'm a little stressed that although the line of the wall is the same, we may have a (very) minor encroachment come Identification Survey and Occupation Cert time. I have taken measurements from the CAD file provided by the initial survey, and it seems fine to me with a measure tape. Are measurements between boundary lines in CAD as accurate as it gets? Cheers!!