Plumber Job in Los Angeles, California

I need the piping from the pressure relief valves on my water heaters changed/installed, permits obtained for the work. One water heater needs the existing pvc pipes changed to cpvc the existing pvc is already installed through the exterior wall so just needs to be changed out with cpvc A second water heater needs the pipes installed from the relief valve through an exterior wall and down the wall so 6" from the ground. A third water heater needs a variance permit because it is on the second floor and on an interior wall which would make it close to impossible to install the pipes. The Dept of Building & Safety said that the permit could be issued because installation would create a hardship.