I love the I series plan and will be ordering the plan soon. Right now we are in the modification stage (figuring out what changes to make). Of course, economics are a concern for us so we are making a number of design changes to be more economical in the building process. Is the barrel ceiling feature built with a truss system that was manufactured and delivered to the sight or was it built on site? How does the prebuilt cost compare to on site construction? I noticed that one of the I series homes on the web site used dog house style dormers instead of the eye brow. Was that done for economic or design reasons. Thanks for any help.