Measure to the bottom of steel lintel or marble, whichever is lowest

Note if protruding bricks interfere with overlap of frame

Note if fireplace floor is higher than hearth extension

If inside fit required, specify sleeve flush with frame

Determine largest rectangle as defined by innermost stones

Chisel down stones that are dramatically different so frame will sit more naturally into the opening

Get a piece of cardboard that is larger than fireplace opening

Cut hole in middle for arm

Tape or hold cardboard so it doesn't move

Reach inside and trace profile

Mark which is inside/outside

To mail template, transfer profile to paper and fold

Follow arch c/w sleeve instructions

Don't try to cut the cardboard the shape of the stones; what we need to know is the actual shape of the required door frame

Be sure to note if clearance from the stones to frame is included in template

Mortar-in frame sits 1/4 inch in from outside of door frame

Width, Center and Side frame measurements required

Photos help in describing/designing complex doors