my Neighbours are changing the height of their roof, our guttering goes from corner of my house to the end of theirs where the down pipe and soak away is, their builder is claiming that i have to re arrange my guttering and make a soak away and new down pipe my side of the house, also the wall the heavy steels need to rest on are the property of next doors house, but i thought it would be a party wall and they would need to give us written notice and a party wall agreement to sign, these steels went in a few days ago and stick out through and into our loft space this can not be right can it, if anyone can give me any information regarding id be most grateful as do not want to go and complain and cause neighbour troubles if it all above board.