When you mention in the answer regarding the "wood framed space." How can we check if it's a wood framed space? The exterior face of the fireplace is brick, but the walls around it are drywall.

The Osburn 1900 Wood Insert must be installed into an existing masonry wood burning fireplace constructed of brick and mortar. It cannot be installed into a factory built metal fireplace. It cannot be installed in a wood framed space constructed in new builds and remodels to house a factory built metal fireplace. Please give us a call if we can clarify further and have pictures available if possible. Thanks!