Legal Question in Real Estate Law in Illinois

The property line is the property line. A survey is just a determination based on the surveyor's study. Standing alone it does not have any legal impact. Perhaps the old survey is correct, perhaps the new, perhaps neither. Newer methods and improved equipment and guidelines tend to favor newer surveys, but the knowledge and skill of the surveyor would be a crucial factor. If an agreement cannot be reached about the correct property line, then a court would have to review the surveys and probably hear testimony from the surveyors (and possibly others) about their methods to render an opinion of what is right. Your maintaining the property may or may not have an impact. Twenty years must pass for an adverse possession claim, for which several other factors have to be established. An attorney can consider whether you meet the factors for a claim, especially if the same property was maintained by the previous owner.