Closest the barrel would be to the brick on the house would be something like 5 feet. It will be in the opposite corner. Pook, what if you built a double barrel out of the 30 gallon drums?
So you guys with stove experience know, but for people who don't, let me tell you about the efficiency. I closed up the stove around 10pm last night. It was a little warm this morning to the touch when I left. I got home around 7pm tonight and the top of the barrel was completely cold. On the bottom though, it was too hot to touch for long. I measured 129*. So I opened the flue, opened then door and everything just looked like cold ashes. I stuck a shovel in and stirred everything up. In two minutes the top of the barrel was reading 150*. In five minutes ALL the coals were burning and the stove was back up to 330+ degrees. All you had to do was set a log in there and you'd be good to go. I'm trying to cool everything off so I can clean it out to paint it, so I didn't relight it. I really have to imagine that people who heat with wood probably only light approximately one match a season.