My Neighbour just built a fence on my property and says that he had a survey done and the surveyor said that it is his property.

The AOLS cannot advise property owners as to their specific property boundaries. It is necessary to employ a surveyor to research the issues and prepare the appropriate survey and report. The legal rights and interests in property are sometimes complex and span the expertise of both surveyor and solicitor. In these instances, it will be necessary for the surveyor to work together with the client's solicitor, and as a team, they can best advise the client.

The science of measurement and data analysis is one of the important tools used by surveyors to express an opinion as to the location of property boundaries. When all the original deed dimensions are correct and all the property markers are in their correct location, then measurements and mathematics may be the most important tools in determining property boundaries. However, the major land settlement in Ontario took place over 200 years ago, some with the benefit of survey, some without. Errors occasionally creep into deeds, documents are lost, original boundary markers are lost through reconstruction and in rare cases, unscrupulous individuals may move property markers or fences or alter documents to deliberately gain advantage. Surveyors must carefully research the history of the property and the physical evidence (property markers, fences, etc.) found in the field and resolve any conflicting information before expressing an opinion as to the location of a boundary. By relying on different evidence, surveyors may arrive at differing opinions as to the location of a boundary.

When differing surveys become known, the surveyors can often resolve the matter and issue new plans and reports. Where surveyors cannot resolve the issues, only a Court or a Boundaries Act tribunal can make a final determination as the true location of a boundary.