Easements defined - there are several variations:

• "An easement is defined as a right, privilege or advantage in real property, existing distinct from the ownership of the land." (Easements in Texas.  1997.  Real Estate  Center, College Station, TX.  Pg. 1.
  
• "A non-possessing interest held by one person in land of another person whereby the first person is accorded partial use of such land for a specific purpose."  (Appraising the Single Family Residence. 1985. American Institute of Real Estate Appraisers, Chicago, IL.  Pg. 15)
  
• "Easements are the right to use property owned by another for a specific purpose." (Property Appraisal and Assessment Administration. 1990. The International Association of  Assessing Officers, Chicago, IL.  Pg. 77)

It is important to remember that an easement is not to be confused with licenses or rights.  They can be vertical or horizontal such as avigation easements (vertical) or pipeline easements (horizontal). When an easement is used to grant a specific access to or through a property it may be called a right-of-way.  An example of this would be a roadway.

Easements can have both a negative or positive impact on real estate value.  They can increase value in situations where the  easement can generate added income (signs), attract desired services (utility) or provide access to an otherwise landlocked parcel.  But, they can also decrease value in situations where the easement is  a nuisance, prevents maximum profitability of land use, or creates a liability.

Easements can be classified in the simplest terms as:

• One that benefits the land owner.
• One that allows someone else to use that property.

However, a better way to classify easements would be by their use. Here we could create three categories.

1. Road easements.
2. Access easements (right-of-way).
3. Utility easements.

Even with this classification there are still other easements that would not comfortably fit the three mentioned.  We will call them "other" easements.

In appraisal the importance of knowing easements and their effects on real estate value is addressed in the Uniform Standards  of Professional Appraisal Practice (USPAP). This document sets the guidelines for appraisal licensing and practice throughout the United States.  It says:

Standards Rule 1-2 (c)

"In developing a real property appraisal, an appraiser must observe the following specific appraisal guidelines: . . .  ( c ) consider easements, restrictions, encumbrances, leases, reservations, covenants, contracts, declarations, special assessments, ordinances, or other items of similar nature."

Therefore, it is important for the appraiser to be knowledgeable of the easement, if it increases or decreases property value,  and the proper way of classifying the easement.  One essential ingredient in the analysis of easements is to study the easement document itself citing all the limitations imposed on the property owner and all the uses the easement could be used for outside of the present use. 

Please refer to the page on electric transmission line easements, gas transmission pipeline easements or avigation easements for more specific information regarding this type of easement.