This story reminded me of a similar case about forty years ago in Northern Ireland. A number of semi-detached houses had been damaged in a bomb blast. The road sloped quite steeply and each pair of houses had different level roofs. When the builders repaired one of the houses they raised the roof to the level of the next pair, instead of raising it in proportion with the other half of the semi. Planners pounced, mainly because neighbours complained that the smoke from the chimney was now not being carried away properly and was coming in their window. After a lengthy dispute, and many solicitors' letters, the roof was allowed to remain, and can still be seen as it was constructed. I cannot say, however, whether the same decision would be reached today. This happened forty years ago when many buildings in NI were bomb-damaged in the troubles and building repairs were a daily event in many towns. I think the local council/planning office had enough to contend with so they let this one go. Good luck with your repairs. I hope you are able to sort it out.