I have a house with a dining room and a lounge either side of an original gable end wall (dining room in the original house, lounge in the extension) I would like to create a fireplace that is open to both rooms i.e. puch a big hole through the wall. Is this even theoretically possible, before I start bothering builders for quotes? I should point out that there is already a working open fire (dining room side) and chimney in place.