Although it’s possible to build a soffit with a depth that matches the cabinets, that design route multiplies the degree of difficulty for the cabinet installer. Making the soffit 1-1/2 inches deeper than the cabinets disguises minor cabinet alignment discrepancies and also permits the installation of a small molding strip. When designing a soffit, allow for an overhang at the exposed ends of soffit runs. Also be sure to allow for the thickness of the drywall on the front and bottom. You don’t need to over-engineer the soffit because it’s not a structural feature. Make sure to build the soffit level and square; it will help simplify installation of the cabinets.
