I'm trying to connect a woodburner to my existing brick chimney. Because of the height of the chimney breast lintel i am restricted to taking the flue from the back of the woodburner. Having made some enquiries i have been told that any horizontal flue coming from the burner cannot be longer than that of a tee piece connector which appeared to be about 3 inches. Is this right. Building regs? I need a piece of flue at least 9 inches, just like her indoors, before i turn it 90 degrees up the chimney through a register plate and then into the original chimney void. I cannot put any of the burner into the fireplace because the hole is to small. The back of the burner will be virtually against the wall. To enlarge the hole involves lintels, knocking out bricks and presumably acros as well. I propose putting a soot door in the outside brick skin of the chimney for sweeping purposes.