Here is my idea, presently I heat my barn with a catalytic wood stove with a single wall stove pipe running up 12 feet to an insulated pipe that passes through a loft and then out through a metal roof. I use my barn to work on my equipment so I need as much floor space as possible so what I am planning is to go about 15 feet along a concrete wall away from the woodstove and put my rocket stove in that location then run a straight pipe from there through a cob bench and then intersect with the woodstove chimney. I was also thinking of using Matt's idea of making it just a stratification bench, my objective is to not only heat the bench but also heat the mass of the NW concrete foundation wall because my barn is built into a small hill so is half below grade, any suggestions would be welcome, thanks, Chas.