Trying to find a wood burning insert and have some limitations. My hearth has an arch opening, this imposes some size restrictions so selection is already a little limited. Real question is the hearth extension... my hearth extends 20" from the brick face of the fireplace. I think I would prefer an insert that protrudes into the room. However after taking into consideration the protrusion (let's say 7" for the Regency Hi2450) I'm left with 13" of hearth protrusion which falls short of the 16" code. Am I interpreting this correctly? Am I stuck with a flush fireplace insert? All the marketing materials show less clearance, though I realize those are just advertising. Any help is appreciated.