Smoking fireplace problem

Bungalow with two reception rooms, both have open fireplace, back to back. If we light fire in one fireplace, the smoke goes up and comes down the other chimney, resulting in the room with no lighting fire becoming smoke filled. Any suggestions as to how to fix this problem?

I had the same problem (albeit mine is a 3 bed semi). Solution is to get a taller chimney pot for one of the chimneys. This stops the smoke from coming back down the unlit one.

how higher?