Yes, if the area is zoned residential, you are not allowed to use it for commercial purposes. You'd have to convince the code enforcement board and/or potential

Yes, if the area is zoned residential, you are not allowed to use it for commercial purposes. You'd have to convince the code enforcement board and/or potentially other relevant authorities that the use was non-residential. Even to make the "weekend getaway with attached server room" argument, you have to be in an area that is zoned for temporary housing.