A relative has recently completed a house extension, done with full planning permission and no deviation from the approved plans. Her immediate neighbours, who were consulted throughout and who replied to the council's initial notification letter with "We have no objections", have now changed their minds and apparently complained to the planning department about issues over blocked light and lost privacy. My relative learned this from her neighbours - she's not had any word from the council on the subject.
What happens in cases like this? Surely key issues like privacy would have been considered by the council and permission refused if the neighbour's rights were going to be violated in any way.