I've built numerous smokers through the years , steel barrels work well if not to much space is needed , right now I have a smoker with sheeting , about four feet high by four feet square works ....but the plan is to build one with cinder block at the lower two feet , a concrete pad , and a small wood stove as the fire box , easier to control the heat etc . This one would be six feet or higher , and about six by six , louvered vents to have better control of the smoke / heat as well as being able to hopefully do cold smoke .....but we'll see how that works