Scenic easements that limit development and types of land uses on property along areas of selected roadways or surrounding historic sites have been utilized by the National Park Service and some state agencies since the 1930s. Protection of the scenic viewshed around George Washington's home, Mt. Vernon, is an example of this. It is only recently however that the concept of easements has evolved into a useful tool for historic preservation of buildings or structures. These easements generally control exterior alterations to a building or site and may require such things as proper maintenance of the property. Many times these easements include other aspects to control the development rights of the lot on which the building stands as well as air rights, which are development rights for constructing additional stories above a building.
Phoenix has a conservation easment purchase program.
The majority of these programs reside within non-profit agencies such as The Historic Savannah Foundation, The Society for the Preservation of New England Antiquities, Maine Preservation and Historic Denver. They can range from the simple to the complex and provide a wide spectrum of opportunities and options. The City of Las Vegas is considering facade easements as one part of its historic preservation program, which would include the downtown redevelopment area. Generally any changes to the exterior of the building must be reviewed and approved by the agency holding the easement. The first of these would be for the grantor to donate the easement.