What is adverse possession in British Columbia and does it exist?

This answer covers the law of British Columbia.

Adverse possession, where long use of someone else's land can turn into ownership, is largely barred in British Columbia. Except as specifically provided by the Limitation Act or another Act, no right or title in or to land may be acquired by adverse possession. For land with registered indefeasible title, a title adverse to the registered owner's is not acquired by length of possession.

The same applies to long use of a neighbour's strip: prescription was abolished, so it does not create a prescriptive easement. An exception is that the Limitation Act does not interfere with rights to land acquired by adverse possession before July 1, 1975. If a building or fence crosses the boundary, the Supreme Court can declare an easement, vest title in the encroaching owner on payment of compensation, or order removal.

The Limitation Act does not apply to a claim for possession of land by a person dispossessed in circumstances amounting to trespass, so the 2-year period does not bar it. A survey showing the encroachment is the foundation of a court application. Your situation depends on the facts, including whether the land is registered, so speak with a lawyer.