H
Ancillary is more like a points system you can add services to a caravan and it still be considered ancillary however if you are already pushing the limits by for example having a none family member live in it you take the whole thing over the limit as to what is ancillary. Don't forget also your work on the services will get more scrutiny than a simple shed and you should get buildings control approval for the sewerage work before you start. It would also be prudent to have electrical work certified.
Ted
