Noting Joan's question previously (~1 year ago) and Cécile's response, I have to ask why «dehors» is/was not recognised as an option in place of «à l'extérieur». I know the usual - can't cover every possibility - reason. However, in practice (at least where I am currently in the east of France) «dedans» and «dehors» are far more commonly used to express inside or outside (the house), and à l'intérieur or à l'extérieur are rarely heard. Suggest this very common and applicable alternative should be recognised.