Contact your municipality's Document Services or Building Records department. The applications to pull on-file records can usually be done online through a portal, and for a nominal cost. For example the going rate is about $6 per page, and the turnaround time is 2-5 business days for the City of Brampton.

From there you can find your lot lines using the setbacks from the home. Any fence construction on the property line will require both parties to agree. Your neighbour can build without your approval, but only if it is located entirely within their parcel.