Notice the peeling paint above the door in this "after overhang removal" photo.
So far we have had to purchase very little wood to complete our repairs. Whenever we have done any demo, we have been mindful to save usable pieces for later use. Most wood that has gone into the trash was severely splintered and unusable. Cedar siding was removed from the front of the house when the overhang was extended back to it's original design. I am sure that during the 70's they removed that overhang in an attempt to get solar gain and help with heating costs. But I am sure whatever gain they may have gotten was all lost by the solar gain they got during the summer. I prefer to have the extreme evening sun tempered with the overhang the way it was originally designed. But back to the shingles.....I kept all the usable shingles and reused them to replace the rotted shingles around the front door. In true "Yankee" fashion, my father and I scrapped the peeling paint off and just flipped the shingle over. Nothing went into a landfill. Another added bonus besides the fact that it was free and didn't add to a landfill was the fact that the shingles had shrunk all they were going to, so the shingles are still nice and tight up against each other.
Notice the used shingles to the right of the front door. These shingles were removed when the overhang was restored along the front of the house.
Oh and the reason we didn't tear it down and start over is because I like what I like and I like old. New I don't like. So until something is beyond repair I'll continue to use it. If by chance my taste change I'll recycle it. Filling a landfill will be my last resort.