I have a home that was built right after WWII, I am in the planning process right now and a year from now install a new metal roof. The roof currently has no eaves or soffit . I want to install 16' overhang on the eaves and soffit. What is the best way to go about this on a existing home. The rafter in the home are 2x6 and are 16 inch on center. Thanks in advance for any input.