@Milkshake Sniffer I can't quote post you so you'll have to make do with this (you).
Solid explanation of the beuraucratic hellscape that is planning permission in the UK. the bit I've always been able to stomach the least is the notion that UK farms were somehow better off for being in the EU when we've already seen what EU policy has done to farmers in France and the Netherlands.
While you're right about the arguments regarding the Part 6 Class A Rights, I'd take the line that this specific line is deliberately vague enough that it gives the council reason to handwave away things they don't like and let through things they do like, as the line implies that 'as long as you can justify what you're doing is reasonably necessary to ensure that agriculture can continue at this spot (ie, diversifying your business in the absence of grants and subsidies from the state) then there shouldn't be any reason to prevent the action being taken.'
There's just as much a point that the works being done would ensure that the farm would continue to thrive were it able to expand its business potential, much in the same way that Daylesford was allowed to expand. Granted, these are two different district councils, but it provides an extremely good illustration of the priorities of each council and how vague enough terms can be used as a form of selective gatekeeping by people with a bad attitude.
Obviously it gets more complex when you start factoring in heritage areas and ensuring that a building matches the aesthetics of the area that it is being built in among other things, but that's something that you can very easily discuss with person who wants to make any changes to their property so that you can come to some kind of a resolution, the problem is that it entirely depends on whether or not the case worker or workers can be bothered to have that discussion with the person who wants to make the change or not, and from my experience the vast majority of people just want to do things EXACTLY as it says in their procedure in to avoid legal trouble from wankers with too much time on their hands who like to complain about everyone and everything and avoid having any more discussion than is necessary because 10 more of these exact same wankers have blocked up the work queue and they start shouting if their queries don't get looked at within the hour.
In the end it all seems to come back to the lowest common denominator, this being the people who complain to local councils, with the council being complicit due to not wanting to deal with complaints from that one nutter who's only satisfaction in life is moaning about his neighbours and maybe going on walks at 10PM (but only if he doesn't have to see or hear any messy farm equipment ruining his dark skies at night. god forbid that country folk actually have livelihoods and try to maintain them).