A serious survey may need to be conducted where ALL the following steps are taken:

1- Without knowing exactly where they will wind up, the surveyor starts at the nearest survey point which may be a distance away.

2- From the survey point the surveyor makes his way to the properties in question and stakes the corners.

3- You can have the surveyor make a map of the area in dispute with the wall sections noted as to where they fall in relation to the property line.

Unless this type of survey is done, the results can be off by more than a few inches and lead to MANY headaches. When this gets to court, this document will be critical. It can be prepared at any time as the earth isn't changing unless the walls are falling into your property. Annual photographs will help as well.