Does anyone have any examples of or references to the legal stuff when someone purchases a house on an entirely residential village and then announces that it's going to become a nursing/rest home on a commercial basis?  I realise the "Juristic person" rules and regs for that village will apply, but are there any Tetsaban/nationwide legal requirements that must be complied with before a change of use can be approved?  Thanks for any advice.  

I researched this topic years ago regarding converting a large home to a legal hotel.  Permission from next door neighbors was part of the process. Off street parking was a subject and fire safety. Local planning departments were aware of this process in Buriram Province when I checked in person with a qualified translator. In the USA when a residential home is converted to a drug rehabilitation center or halfway house, local regulations come into play and Thailand is not far behind on such regulations. Enforcement can be selective, such as no smoking rules for a restaurant or bar in Buriram. I suggest the OP go in person with land papers to the local planning department along with a very good translator to research the local regulations. Police and army have been paid to enforce actual regulations in Buriram regarding smoking at a restaurant. A strict enforcement of existing laws can be accomplished by motivated government or army folks.