Satamax Antone wrote:You have about 3 cubic metre of stone, that's about 8 metric tons (well counting like massonry, if it was pure granite, it would be heavier) So, that's plenty enough.
Now, you have to decide how you want it to look, and if it is possible to keep the chimney as is, and have enough ISA (internal surface area.) for it to skip the front bell as i have drawn it. Can you calculate the ISA of the fireplace and chimney?
Allen had a point about insulating the stonework on the outside. I would go strawbales and cob. But i'm sure there's other options.
These are the measurements that I find on the fireplace as it is INSIDE and OUTSIDE the house, including the depth of the stone from the outer edge in the room to the surface of the wall, as well as the depth from the outside wall to the outside edge of the stone.