Share your experiences with concrete roofs

Due to our elevation, we have significant sub-zero temperatures in the winter, horizontal snowfall from the valley side and, in addition, clear sunlight in the summer. We are planning a gable roof with a 35-degree pitch, and the architect suggested making the roof in concrete (precast or poured, he is currently considering the former option). One of the advantages of this would be that the house would not heat as much. We are also planning to build a black house and will use bitumen for the roof.

Does anyone have any experience with a concrete roof? If so, can anyone report anything (advantages, disadvantages, cost)? Currently, a 150 sq ft roof area results in an additional cost of about 15000 euros with all the trim.