What kind of structural construction on first floor of a single storey house would require MCD permissions?

what kind of constructions on the first floor of my single storey house would mandatorily require MCD permissions and what could pass off as "temporary constructions" and hence not require formal permissions and passing of the house plans by MCD? Are "temporary constructions" defined by height of rooms/walls, or type of roofing or dimensions of the room, or type of construction material used, or what? No clarifications on this subject exist on the MCD website. Would appreciate an authentic reply!