You have to make the choice between building a cheap basement by slapping paneling up on the walls, T-bar on the ceiling and low-grade carpeting on the floor, or taking that buried treasure beneath your feet - your basement - and creating a beautiful new extension to your home. You should build a basement with the same quality as the rest of your home. Building codes and proper construction methods should be followed. For example, since your basement is surrounded by concrete walls and floor, cold and moisture are big factors and can cause mildew and bad odors.