Almost anything is possible, with the right tools and design ingenuity. But I would not do it, no matter how much I want the fireplace on the other side. It's risky because the way the chimney is shaped is to ensure an updraft when you light a fire. If you break through a wall to make is 2-sided, you alter the shape, probably in unpredictable ways, and you may not get as good a fire as you have now. It would also be a very messy and expensive alteration. You are likely to end up with an entirely different fireplace from the one you have now, not a nice old fireplace that's now 2-sided.

But I'm just a layman. What do I know? You might want to pose your question in the chat room at hearth.com. The people there live, sleep, and breath fireplaces.

thanks for the info