REALTORS® are generally familiar with adverse possession and prescriptive easements--the acquisition of rights to another person's property without their permission. The law in this area has undergone considerable change over the last few years, and several recent opinions by the California Court of Appeal continue this trend.
By way of background, adverse possession and prescriptive easements each involves the unpermitted use of another's property for five years. After five years, an adverse possessor may acquire title to the affected property; with a prescriptive easement, you get a continued right to use the property, but not title. A key difference between the two concepts is that an adverse possessor must pay property taxes for the affected property, while one can acquire a prescriptive easement without paying taxes.
In the recent cases of Harrison v. Welch and Kapner v. Meadowlark Ranch Association, the Court of Appeal examined the law of prescriptive easements and concluded that the unpermitted use of another person's property that is "exclusive" (that prevents the true owner from using his or her land) generally will not give rise to a prescriptive easement. The court did not question the validity of "traditional" prescriptive easements, which are created by non-exclusive use of another's property with no permanent occupation (classic examples might include walking or driving across someone else's property to access your own property). But in the court's eyes, awarding a prescriptive easement to one who makes exclusive use of another's property is akin to awarding full title via adverse possession without the requisite payment of property taxes.
These recent cases will likely affect many boundary disputes. In the past, a property owner who constructed a fence or other encroaching structure over a boundary line might have claimed a prescriptive easement on the neighboring property after five years. Now, that argument would be much harder to make since the encroachment would probably be deemed an exclusive and permanent occupation of the neighbor's property that would not "ripen" into a prescriptive easement. (Granted, there are other legal arguments as to why such encroachments might not have to be removed. But after these recent cases, the law of prescriptive easements usually will not be the reason.)