Sky installation advice.

[ABA]

if any part of your dish sticks up above the apex of the roof you need planing permission don't matter about size of dish even if its only a zone 1 dish
below the apex you can go up to a 1 m without permission providing its not a listed building

[TheBadger]

With regard to planning permission it really depends on your nieghbours and your council. If your neighbours don't mind the dish then the council are unlikely to find out about it. So you could risk installing the dish and apply for planning permission retrospectively if necessary.