Using polystyrene in a basement
I'm starting to plan my basement remodel project and one thing that I've been researching is hanging 1/2 inch polystyrene (XPS) insulation on the walls before I frame. The house is only 3 years old and the builders insulated the walls from the outside. I'm also not planning on insulating the floor. Is it necessary that I hang the XPS or am I just wasting time and money?