The 5695 instructions are written awkwardly but what it says employs a double negative. It basically says that no cost relating to solar such as a roof or portion thereof will fail to qualify solely because it constitutes a structural component of the structure it's on. Meaning just because the house would need to have a roof anyway doesn't mean that the cost would not qualify for the solar tax credit. It actually says it more forcefully that no costs relating to solar will fail to qualify. I would definitely encourage anyone confused by this to consult a licensed CPA, even better if that CPA has solar and has looked at this closely.
On a side note I've been working in solar for half a decade and have never had anyone ever run into trouble including the roofing cost for the solar tax credit but people should limit themselves to the roofs that have solar.
