Planning permission will almost certainly be required, but as others have suggested it might be prudent in the first place, if you have significant concerns, to pop in and have a word with the business operators. I'm not (in part because professionally I can't) condone anyone who breaches planning control, but it might be that they are in the process of applying for planning permission - many times in my LPA days small businesses would submit applications which were woefully lacking in detail or accurate plans and it would then take several weeks of dialogue between the LPA and the business for a valid application to be submitted.Or they might tell you where to go, in which case you then have no qualms about going to the Council.
Adam Beamish ● 2222d