Make sure everything is in writing and refer in writing now to anything that was not put in writing earlier. Perhaps getting the insurer involved is still a good idea. Be utterly open with them. Tell them about the stop work orders etc to demonstrate that the OC has tried to do everything by the book. Write to the owners generally with the insurer’s advice. They should know that they have a neighbour who is jeopardising their interests and that the executive is doing all it can to protect their interests.