I have a large 3 season room attached to back of my house off my dinning room, approx. 15x20'. My wife and I recently purchased the 50yr old home from the original owners who added the 3 season room back in 69'. By looking in the crawl space, which is accessed from outside the home, the beams and plywood seem to be in remarkable condition. My question is how should I go about insullating the floor for this project. The crawl space is about 3' high with an earth floor. Also I'm located in upstate New York. Thanks for any input.