The roof is cedar shingles; blue label, re-sawn, and rebutted. Depending on your location or house insurance, cedar shingles may or may not be allowed or covered by insurance. Hope this helps, good luck on your project.

Cedar shingles with a small metal portion on the left. It also looks like they've accented by using copper for flashing and valley metal. While TEA2 Architects is absolutely right about it often being a liability with home insurance, there are now many synthetic products that mimic the look of shake roofs, without the fire hazard, and with better longevity.