I ve been to price a new boiler for a customer of mine who has told me the building is listed. There is currently a balanced flue ideal Mexico 2 there and the new flue will go back through the same flue hole and be bricked up around it in the same stone but it's never going to be a perfect match. What I want to know is where do I stand with the planning? Customer just wants me to go ahead and do it but I'm a little concerned it will be my problem not theirs if the council don't like it. I ve done brand new installations on listed buildings where I had to get permission for the flue but this takes 6 to 8 weeks and the boiler is a non op at the minute. Are the rules different if it's being flued back in the same place? Thanks