I realize this is a little mean, but if you fashion yourself "competent" in white-collar things it has no or negative relation to a building project, at least in the US (I realize trade culture is different around the world). You need to be a bulldog, and a competent and skilled one in all manor of things, to drive a project like this. Otherwise, that is what you are paying the general contractor to do, and that is the most important person on your job - beyond the architect, and especially vanity consultants. This person made a huge mistake in not being 100% comfortable with their builder before embarking.
Most of this heartache could be avoided with two principles in my opinion: 1) do the harder thing (i.e. pour concrete), 2) build as close to commercial code as you can afford (i.e. find a commercial builder if you are chasing specs like this, a mechanical company to do this vanity HVAC work, etc).
Most of this heartache could be avoided with two principles in my opinion: 1) do the harder thing (i.e. pour concrete), 2) build as close to commercial code as you can afford (i.e. find a commercial builder if you are chasing specs like this, a mechanical company to do this vanity HVAC work, etc).