And because the Mexicans aren't paying for it, I'm looking for something
adequate (and which meets any regs) but not over-engineered.

It'll be an outside wall, no windows, and from the outside in:

One thickness of bricks
Some form of insulation
Studwork/plasterboard
Kitchen cabinets

I'm hoping that a hybrid approach will reduce:

the depth of foundations
the overall wall thickness

....compared to a conventional cavity brick wall plus plaster.

I'm even happy if it turns out to be more insulated.

It'll have a fairly lightweight flat [yes, I know] roof.
--
Roland Perry