A deck house seems to be a transatlantic term for our term “Timber framed buildings”. Normal/ UK construction would require the timber frame panels to have an internal surface of plasterboard followed by a pvc vapour barrier (or integral with the plasterboard) the insulation, racking board (to prevent twisting of the frame), a “breather membrane”, a cavity and then the cladding. I suspect that the “Infiltration barrier” is the breather membrane as it also serves to keep moisture out of the frame but allows moisture to escape. If the render has been applied to the surface of the panel on top of the breather membrane then it will also need to have expanded metal or similar to allow the render to adhere to the panel. If the render has cracked at panel joints it is possible that the expanded metal has not been continued across the joints and is thereby causing a weak point. A better detail would have been to have a space between the breather membrane by fixing a vertical batten (protected with a pvc dpc) and a layer of expanded metal to which the render could be applied. Suspect some “additional investigation” may be asked for?
Just for the record my first job out of college was for a company know as Timber Structures (Oxford) Ltd who used the “Minox” system of timber framing.
Hope this helps.