The planning rules in Northern Ireland are different to over in Britain or from south of the border in that local councils are currently not responsible for them, they're are arm of the Dept. of Environment. However they are being mostly transferred when the new councils are in place in April, I'm not 100% sure of the ramifications other than the councils will now be responsible for their development plans.
In saying that, the basic rules regarding satellite dishes here are I think the same as in Britain (
document here, PDF) - if the building is less than 15 metres tall then two antenna are allowed, one no more than 1 metre and another no more than 60cm in any linear dimension, which is a bit stupid over here considering that a Zone 2 dish which is some 75cm wide is almost always used for Sky reception - the old analogue regs at least noted that a single 80cm dish was allowed without PP.
I'm not one to say "**** the planning office!" because IMO there are reasons for their existence to ensure fairness of application (as well as not wanting an animal rendering plant located next door to me!) but inconsistencies can be a pain in the arse to deal with. Someone pointed this out here a while back in that someone could just dump an 8ft x 8ft x 8ft garden shed in their back garden and no eyelids would be blinked, but someone wanting to put in a satellite dish half its width and/or height on a patio mount would need PP. Another inconsistency I can give is that when I was still living with my parents, we had a new expensive terrestrial aerial setup installed which had a large UHF Group A for NI terrestrials, a mid-sized Group C/D for TV3 and TG4 from the Republic and a 10 element VHF Band III aerial for RTÉ 1 & 2 on a 15 foot pole on the chimney with no planning permission required. Because we lived half way up a hill (the wrong side for TV reception, hence the need for bigger than normal aerials), the array could be seen nearly half a mile away! It's still up there though I did take the Band III aerial down myself in the summer of 2012 (I'd moved out by this time) as it would have been redundant in a couple of months with the digital switch over here on both sides of the border, and the southern channels were available on Saorview.
At present, as my previous setup photos have shown, I have three dishes at ground level in my back garden at my current place, one 1 metre motorised on a patio mount, one 80cm multi-LNB attached to a washing line pole(!) and a Sky Zone 2 dish attached to a steel pole that is secured to a wooden mount buried under the soil. Technically my set up requires PP, in fact there is a fourth dish on the property high up on a side wall which was an old tenant's Sky dish that I haven't got round to removing yet as I don't have a ladder tall enough to reach it (it was already blown out of alignment before I moved in). However my back yard array can't be seen from any main road, and the road of the cul-de-sac estate in can at best only see the top third of the 80cm dish. There are a number of neighbouring back gardens in view of mine given the nature of the place, but I've had no one say boo and I try to make sure my neighbourly relations are good (basically, don't be a dick). The wall covering two sides of my heating oil tank is arguably more annoying to look at. A couple of them have even asked about the set up in interest. If the time comes when I get a letter querying about needing PP for the set up, then I'll simply try to comply - I keep my costs low where I can on this hobby, the thought of PP costs don't appeal to me and I tend to be a bit of stickler of not wanting to create too much fuss. There doesn't seem to be much enforcement of the rules of satellite dishes locally however, I my short time at the local planning office I never came across one enforcement notice or report on such, and at a block of flats I used to live in which wasn't more than 15 metres tall on the ground, there were at least six satellite dishes on the wall despite (a) only two being allowed excluding PP and (b) the fact that all tenants were supposed to get permission first from the housing association before getting the dish installed! So I think I'll be OK as long as I don't start completely taking the piss! I have the Sky dish pained silver to blend in better with the stones on the ground though I have a Zone 1 dish waiting once Astra 2G comes into service and Eutelsat 28A and Astra 2A retire, the rest of the dish painting will have to wait until better weather comes.
Would I like to see planning regulations changed regarding satellites dishes to allow bigger sizes as long as they make some consideration for their local environment? Absolutely. However as satellite enthusiasts we don't really have enough numbers to force some kind of political pressure for change on this compared to those who own garden sheds, or (locally) needing large TV aerials for cross-border reception. It could be worse though, like in some parts of the USA where you can't even change the colour of the walls of your house without getting permission of the local home owners association.