I have recently bought an old house which is without cavity. 2 rooms in particular (1 up 1 downstairs) are quite cold due to having 3 external walls. as well as other remedies I would like to install a log burner in the lower room and then run the flue/chimney through the floor and exit via the upstairs room wall. where would I find advice on the regs required? Has anyone done anything like this before? does it help? Will it mean I need to leave a gap around the flue in the timber floor? Thanks in anticipation. simon