ausdesign
I would assume that if there was a cavity and it was enclosed top & bottom then there would be an advantage gained thermally by the internal mass plus the still air space.
If the cavity was 'open' then the internal skin of brickwork would work negatively.
If the cavity was 'open' then the internal skin of brickwork would work negatively.
This is correct. Still air is a great insulator. Less convection means better insulation. I have in correspondence with a builder/architect who used brick, frame, gap, aircell on battens, gap, external cladding.