IIRC you have to actually get planning permission to change the use of the house from residential to business. The council website has further information, but I can't be bothered to go and find the relevant pages -- sorry, am lazy! But I had to look all this up when we were trying to ascertain whether we'd get hit by those sorts of laws when trying to change two flats-for-rent into one house-for-owning. (We didn't.)