I found this via Matt (vcahmco) He also likes the brick accents. Concrete is such a terrific material for zero egress entry. The use of the brick on the outside livens it up without increasing cost much or decreasing safety.
Use spring form cake pan, a dollar store round aluminum foil cake pan, or round plastic garbage can lids to make the circular. Use recycled pizza boxes for square designs and dollar store rectangle aluminum cake pans.
Mendip Churchill wood burning and multi fuel stove we installed in Bradford recently. We knocked out the customers chimney breast to reveal the original brick work at the back, supplied a slate hearth and oak beam.