Deralte
The roof is going to be a combination of synthetic slate (Lamarite) on the main roof and standing seam on the dormers, porch roof, and tower.
The walls are presently insulated in fiberglass with the paper backing toward the inside. However, since all of the windows and doors are being replaced, we will be stripping the sheet rock off of the exterior walls and re-insulating. We are also stripping the cedar shake siding off of the exterior, so will have access to both sides of the walls and can start from scratch on insulation material. The only thing we're stuck with is the 2x4 construction of the walls. Our objective is to provide a thermal break to come as close to the performance of a SIP as we can.
That brings up one more issue. Since the SIP's will provide the insulation for the outer shell, should we remove the existing insulation from the attic storage areas? By the way, this is a 1962 raised ranch that we are trying to make look like it was built in the 1920's. Thanks again.