Warning, this is pretty long and there is a diagram attached. I have a new client that I just did repairs for on an existing system (home he just recently purchased). He has a large amount of property for a residence and already has a 12 zone system installed that covers the basic highlights of the entire surrounding residence. That being said, he has a large field in the backyard past the existing irrigation coverage that he is interested in irrigating. I did take offs and with a basic rotor head to head spacing he will need another 4-5 zones depending on the pressure I get from the existing system. Well there are a few obstacles. First, the RB ESP modular is maxed out and couldn't handle 5 more zones. The controller is only a few years old and is completely dedicated at this point. If I were to upgrade to a rb esp lx me I could incorporate the entire system, but the original clock would be a waste and I would have to run 18/7 about another 120 feet from the original controller to the valve locations I have in mind. I have included a pic to reference below. Ultimately, a new RB controller with 18 zone expandability, 120 feet of 18/7 and a complete rewire of all incoming wires would cost him about $850. I offered him another option which he appeared to like much more, a simple RB esp with one module to cover the 5 new zones and have room for future expansion. I would then simply run a common and master wire from the original controller to the new, 60 total feet in the basement(original system is controlled by master valve so the new controller would have to open it as well) and only charge him $260 for all of that. He sounded much more pleased about simply having 2 controllers at 1/3 of the price as opposed to one commercial controller handling everything. Now onto the next order of business. The main line never even comes close to entering the back yard, in fact it terminates at manifold 3 which ultimately has one zone line going to the backyard. My plan was to cut out valve 12 at the manifold and then couple back the pipe using it as mainline to the back yard, then reinstall zone 12 valve right before the closest head on zone 12. This way I now have mainline to tie into without having to trench all the way around the house to get to it and run all new pipe. Ultimately, from this point I would Tee into the main line and begin feeding main to valves covering the lower field. Any suggestions or differing opinions?