I'm looking at building a basement entrance / mudroom at my walkout basement door. It's at the corner of the basement. I have concrete block walls that are not finished with any type of wall covering other than paint. I'd like to enclose the door with a small room that will allow us to walk in and drop our boots after we're done working in the garden or shoveling snow off of the patio. I want to insulate it so that the room can be a thermal break. The exterior door doesn't seal the cold out very well. Also, I don't know if putting foam panels on the concrete walls inside this room would be necessary. I also plan to insulate the basement walls and finish them. I'm trying to decide how to seal any air leaks at the edges of the walls at the point where they meet the concrete walls. Spray foam might work but if anyone has any other suggestions I'd like to hear them. Any other suggestions or concerns on the construction of my addition would be appreciated.