This plan for a Temp-Cast 2000 masonry heater with chimneys on each side has been a very popular configuration over the years. The active chimney can be on either side. The other chimney can be decorative only, or it can service a lower level masonry heater, or it can be used as a wood storage box, bric-a-brac shelf, etc. This design is particularly impressive in a larger room with a cathedral ceiling - an open arch can be used above the masonry heater or the chimneys can be corbelled towards the center above the heater. (Note that dimensions assume a 4 inch facing material.)