We live in a very well built brick bungalow, circa 1945, in central North Carolina, a very temperate climate. The house has a full basement, with concrete block walls and poured concrete floor. There are no cracks anywhere and the basement is water-tight. Because our lot slopes toward the back yard, the rear portion of the basement (where we plan to put my teen son's new bedroom) is about half above grade, with windows that let in good light. I'm very tempted to just put a high quality paint on the walls and the floor joists above, put in flooring, and call it a day, because the space maintains a constant temperature of 70 degrees year round, even with no AC or heat source. Is there any reason why I should do more than this? Resale is not a consideration. BTW, my son couldn't care less about how his room's finished. He's a senior in high school and in a house full of females. He just wants his own space to get away ASAP.