An easement is one  way that a person may be allowed to use the real property of another person for a certain purpose.  There are different types of easements, including the easement by necessity, sometimes called the easement implied by necessity.  

For an easement by necessity we need two things (i) severance of title; and (ii) necessity of an easement at the time of severance.

Severance of title means that we have a piece of land that was originally owned by one person but then is transferred so one person now has title to a portion of the land and at least one other person has title to another portion of the land. Let’s say O has property next to a road on the east and surrounded by trees on all other sides.  O divides the property and gives A the eastern half of the land next to the road and B gets the west.

But now B can’t reach the road without crossing through A’s property.  We can say it is necessary for B to cross through A’s property because he has no alternative but to do so.  

We satisfied our two conditions above because at the time there was severance of title – – when O transferred the land to A & B – – it was necessary for B to use A’s property to reach the road.

Below is a video on easement by necessity: