Abstract: A building roof consists of an assembly of adjacent roofing units, each comprising a pyramid-shaped main section of which the lower edges lead into, and are secured to, a rectangular peripheral assembly of channel ducts, the adjacent ducts of succeeding units being connected and sealed. Fascia units are secured to and extend outwardly from the outer flanges of the channel ducts about the periphery of the roof, each fascia unit having a sloping top substantially co-planar with the pyramid surface secured to the inner flange of the duct, a substantially vertical outer face, and a substantially horizontal bottom leading back to and seated on an exterior wall of the building supporting the roof.