The garage condo build is a superb execution of an excellent concept. I am just trying to find a cheaper easier way. What about a redesign of one truss. It looks like they are about 6' apart so a redesign of one could get you a vaulted ceiling with 12' of space available for the mezzanine. Partially I have issues with going lower with the floor based upon my location, we get wet here, water drainage is the first concern when planning a building, we don't have basements in houses in large part because they would constantly have water issues. I have trouble with the pit concept, let alone a pit in a basement (lowered floor), to me it looks like it would be a pool but likely not where you are at.