We have about a 35 year old home that we added a second story to about 10 years ago.  Now we are remodeling half of the original first floor.  When we added the second story we added a inch of styrofoam insulation  before siding with vinyl.  Since we gutted half back to the studs, should we go with open or closed cell.  General contractor says they tend to use open since it will shift with a new building, but this one is pretty much past that (I hope), so should we go with the closed cell for better R value, or is there a reason we should use open.  Thanks for your input and opinions.  I wish foam was an option when we did the rest.