I am proposing to do a loft conversion above my first floor flat. This will involve putting in a new staircase which will start from my landing above the existing stairs. As the first stair is sitting on the existing floor, it will put a load on the floor (all be it a small one). Does anyone know if this requires me to provide a “party wall-structure” agreement with the owner (and freeholder)? I have informed them that I am getting planning and building regs approval before starting work. Also, there will be an increased loading on the load bearing walls where the increased floor load will be transmitted down to the foundations. Does this have any involvement with the “Act”.