A Negative Easement is just the opposite of an Affirmative Easement. A Negative Easement prohibits a landowner from doing something. One common example of a Negative Easement is a restriction from building an obstruction on the Servient Estate. Unlike Affirmative Easements, Negative Easements do not give anyone a right of entry onto the Servient Estate. Instead, Negative Easements essentially give the Dominant Estate the right to prevent something being done on or by the Servient Estate.
There are many common examples of Negative Easements. One common example may be an Easement that requires one neighbor to maintain a fence, tree line, or driveway for the benefit of another neighbor. Another example of a common Negative Easement may be an Easement that gives the Dominant Estate the right to receive light, which is essentially an Easement that prohibits building a certain kind of structure that is likely to place the Dominant Estate in its shadow. Other examples of Negative Easements have included the right to the flow of air through a defined opening, and the right to keep the owner of the Servient Estate from building within 35 feet of the edge of the property.
The key to determining whether something is classified as a Negative Easement is to determine whether the owner of the Dominant Estate is given the right to force the owner of the Servient Estate to refrain from engaging in a certain activity on the Servient Estate. Courts are not particularly fond of Negative Easements because they tend to go against certain American ideals like the right to privately own land, and the rights to do what you want with the land and to do what you want on the land. As such, the courts have largely limited the use of Negative Easements to a small list that includes Easements for air, the flow of an artificial stream, light, and for Subjacent or Lateral Support.