I've tried looking for an answer to my insulation woes but I just get cross answers. I have a house built in 1953 in the Washington DC area. I was able to increase the insulation in the attic last year and I hope to do something about the walls soon. They have nothing but a fiberboard sheathing and old siding. I want to replace the siding which seems like a great time to do some air sealing and insulating. But how much and what options to choose is the question of the day. I have heard that blowing in cellulose from the outside without a vapor barrier on the wall side is a bad idea. I've read that if you vapor barrier the outside and then a layer of ridged foam that the cellulose is ok. Then there is insulated vinyl siding to consider. I know it only has a R value of about 2 but every bit helps doesn't it? I need help. Whats would be the best option without tearing into the inner walls? If you don't blow in cellulose should you house wrap then foam board on top? Please guide me out of this mess.