[organsnyder]

This is accomplished in new builds with intentional ventilation. My above-garage ADU accomplishes this with a schedule on the bathroom fan and a make-up air intake in the utility closet. A more expensive (and more efficient) route would be to install an HRV or ERV.

As an energy consultant friend explained to me: You want to control the ventilation rate, rather than relying on whatever you get accidentally (which may not be enough, especially on calm days).