An appliance includes a metallic outer wrapper having sidewalls, a wrapper backwall and a machine wall. At least one metallic inner liner has liner walls and a liner backwall, wherein the metallic outer wrapper and the at least one metallic inner liner are coupled together at a trim breaker to define a structural cabinet having a hermetically sealed interior cavity defined between the metallic outer wrapper and the at least one metallic inner liner. The trim breaker defines a front face of the structural cabinet. At least one trim breaker conduit extends through the wrapper and liner backwalls wherein the trim breaker conduit defines a conduit through the structural cabinet, and wherein the structural cabinet is hermetically sealed at the trim breaker conduit.