Tenn. Code § 13-7-103
Such regulations shall be designed and enacted for the purpose of promoting the health, safety, morals, convenience, order, prosperity and welfare of the present and future inhabitants of the state and of its counties, including, among other things, lessening congestion on the roads or reducing the wastes of excessive amount of roads; securing safety from fire and other dangers; promoting adequate light and air, including protecting and encouraging access to sunlight for solar energy systems; preventing, on the one hand, excessive concentrations of population and, on the other hand, excessive and wasteful scattering of population or settlement; promoting such distribution of population and such classification of land uses and distribution of land development and utilization as will tend to facilitate and conserve adequate provisions for transportation, water flowage, water supply, drainage, sanitation, educational opportunity, recreation, soil fertility, food supply and the protection of both urban and nonurban development, and identify areas where there are inadequate or nonexistent publicly or privately owned and maintained services and facilities when the planning commission has determined the services are necessary in order for development to occur.
T.C.A. § 13-7-103