Ok thanks to all of you that shared ideas with me, I think i have it. I'll start with 4' w x 4' L x 8' H 2x4 framed structure. Then on the outsie use a cement hardie board. On the inside i will use a non treated sheet of plywood. I will use standard roll insultion between the walls. The roof will be made of tin sheets. one 55 gal drum to use for the wood burning to get my smoke channeled through pipe into the house. now if this sounds like it will work let me know, if not let me know. If you have any modifications that may help please let me know. Thank you for your help.