Thanks for the replies. What I meant by half the layout is I halve the Z4000 powering one side of my layout and a Lionel Power House powering the other half divided into two power districts. I think I will get under the layout and just connect each building one at a time to so if there is a short in only one. I will get a separate transformer just for lights. I am looking at getting the woodland scenics Just Plug system for the three woodland scenic buildings. And maybe another Z1000 for the rest.