I know this topic has been reviewed what seems like a thousand times, feels like I've read them all too. Anyways, I'm replacing the aluminum siding on our 50 year old house with vinyl siding. I've been trying to get our home up to snuff on insulation for a few years now. It is a 1500sqft ranch on a crawl space. Two exterior sides are brick and the other two, siding. Currently there is only a thin batting in the walls, seems to be a 1"-1 1/2" batting with tar paper face, maybe something they used in that era. The walls are extremely cold in the winter months, we live in Northeast Indiana, I believe it is a zone 5. By this table on the energy star website, http://www.energystar.gov/index.cfm?c=home_sealing.hm_improvement_insulation_table , I should blow in insulation and add foam sheathing. My thoughts on this are how well would the blown in work with the old sheathing in there, I don't know if it would be able to fill voids well enough, and the other is that I would like to avoid adding 1" sheathing and having to frame out windows, doors, etc. I keep coming back to the idea of removing all exterior sheathing and using expanding foam insulation only and new sheathing, wrap, siding. Any ideas, personal experiences, professional tips, would be GREATLY appreciated on the best way to continue.