External Obsolescence

A loss of value (typically incurable) resulting from extraneous factors that exist outside of the property itself; a type of depreciation caused by environmental, social, or economic forces over which an owner has little or no control. If there is a change in zoning, external obsolescence is likely to occur, as in the following examples: to a residence if an industrial plant is built next to it; to a well-maintained house in a deteriorating neighborhood; and to a motel if a new highway is built that results in difficult access to the motel. Other causes might be proximity to nuisances and changes in land use or population. Also called locational or environmental obsolescence.