Joint house: disagreement between co-owners for development, coercion.

We have a Ancestral property ( a house) in which we live on first floor ground floor is shops, it was partitioned between our two ancestors, our grandfather( party A) and his brother( party B)( so the house was divided in halfs from middle, the architecture of house is such that the stairs are from the middle). Now party B wants to develop the property but before developing they have to demolish it and if they demolish it whole of it will fall because it's one house approx around 2500 sq ft. So our part will also get damaged and fall. We are not interested in reconstructing our property as its good for us. They have sent a local TMC goon with a agreement for us to sign which mentions that we agree to this contract between us and he(goon), whereas he ,via agreement between he and xy developer( who via a agreement between xy dev and party B is appointed as the developer), is appointed for demolishion of the property and any damages to my property will be born by goon and after we sign this we can't appeal to court and has to be settled mutually. We don't want to be hindrance in Thier work but don't want to cry later on as have been witnessed in several earlier occasion, I believe the property could be developed without damaging our portion but for that they have to leave some portion from their part and then develop then it will not effect our part but they want to start building right from the border and want us to leave some part for municipal boundaries From our part to which we don't agree.