CHATTANOOGA, Tenn. (WDEF)- Financial experts found Chattanooga to be the lowest cost of living for household bills. “Our average rents and mortgage rates here in the Tennessee Valley are probably 20% lower than the national average, which is helpful. In addition, thanks to TVA and our proximity to TVA, our electric bill here is about 25% lower than the national average.” said Chris Hopkins with Apogee Wealth Partners.