In the absence of local codes we suggest your installation clearances meet or exceed the national standard building codes or the national fire code.
Tile in front of fireplace code.
Tile is not recommended for applications that will exceed 175 f 80 c so it s not an option for the firebox.
It is the part that is most visible.
Combustible materials and trim must be at least 6 inches from the firebox opening.
When the opening of the fireplace is at least 6 square feet the hearth extension needs to extend at least 20 from the front of the fireplace and 12 on the sides.
Mantel corbels and brackets attached along the sides of the opening must have additional clearance if they project more than 1 1 2 inches out from the face of the fireplace.
National standard building code information.
2114 3 masonry built fireplaces 4114 3 10 all combustible mantels and similar trim shall be kept at least 6 inches from the fireplace opening.
National standard building code.
This is illustrated in the diagram below courtesy of the fine folks at code check.
The surround is the front facing portion of the fireplace.
The hearth design must be.
The firebox is where the actual fire will be and it must be lined with the appropriate materials that will meet building codes.