I think the best way to make your roof and your home green is by installing solar panels atop your roof, though it is an expensive investment they will pay for themselves over time with the amount of electricity that you are going to be able to save.
sarah@diy solar panels´s last blog ..How Solar Ovens Work

Another great alternative is to use solar shingles. You can generate enough energy in 8 squares of a 40 square roof space (1 square = 10×10 area) to power your home according to the standards released by some of the more modern solar power shingle manufacturers. You can help the environment by cutting down your carbon footprint.
Fireman Roofing´s last blog ..Old Wood Roof Shingles

I had not given my roof much thought, but I will now.

Bens last blog post..“We’re All Going On A Green Holiday…”

[...] at Groovy Vegetarian. Clara wrote in to tell us how Green roofing options are plentiful, but to make sure you do the required research. According to Jacques Sprenger, Living cheaply can translate to living green, as we cut down on the [...]