All Mugnaini residential factory built ovens must have minimum clearance to combustible construction.
The ovens require a 2” clearance on back wall and side walls to any combustible materials. Do not pack the air gap with insulation or other material. You may bridge the gap between the oven and façade wall with metal stud framing and concrete board. A metal stud may be fastened directly to the steel sides of the oven. Use ½” Durock brand concrete board, or similar, to transition to any wood framing.
Complete instructions can be found in the Residential Manual.