Three‑piece lintel over a 48″ opening, trimmed with 2″ flat infill panels around an Isokern Standard 42 firebox, on a chamfered three‑piece hearth.

Approximate, for design review. All joints 1/4″. Final dimensions are on the shop drawings.
A galvanized steel angle at the lintel soffit carries the three‑piece lintel. The lintel joints fall over the opening, so the center piece bears on the angle.