Neighbours extending balcony without permissison.

My parents live alone in the ground floor flat of this building constructed in 2012. Now after 8 years the above 3 floor neighbors want to extend the balcony to the same size as ours. Problem is that my mother suffered a brain stroke in 2019 and is not in a position to move much and is asthmatic too. She is not in a position to allow any construction activity and is allergic to dust. Today one of the neighbor called me and said that my permission is no longer needed and he would be putting scaffolding from the parking right to top floors to enable construction. I have told him that let me seek legal opinion and if the law says you can go ahead you may go ahead. What is my legal stature in this regard? In 2016 building bye-laws were tweaked to allow bigger balconies upto 5 feet but they want to extend it to 8 feet. My senior citizen parents are being harrassed whenever they pass the common area and remarks are being cast upon. Both my parents are 70 years old. what is the legal recourse available. Are they entitled to extend the balcony without my permission?