Thank you. The local authority will argue that is not ancillary. It is self-contained accommodation which is probably why you are having the problem. I appreciate that you say that it is not used as stand-alone accommodation but the fact remains that it could be.
If it is only been on the site for a few months, that’s the problem.
Without wishing to appear harsh, the fact that your parents now have nowhere else to live is not relevant because clearly, they did have somewhere some time ago.
I appreciate it isn’t permanently fixed to the ground but he doesn’t a touring caravan that you could just simply put behind your car and drive away.
If they have turned down planning permission, and you want the best chance of appealing being successful, then I would suggest that you use a planning consultant to submit the appeal for you. Not a solicitor, not a barrister, someone who deals with nothing other than planning.
You prepare the appeal now and you submit it close to the deadline because that buys your parents more time.
If local authority planning has already been refused, then you have really done as much as you can do in appealing.
If there ends up being an enquiry about this, you must attend otherwise your appeal carries far less weight.
If you could please rate my service five stars (even if it’s not the answer you wanted) that would be really helpful. If you have any further questions you want to ask on this subject, I am happy to deal with those for you.