A one-piece sheet of light transmitting plastics material or polycarbonate is vacuum-formed to produce a skylight glazing or pane, a surrounding curb portion and a surrounding flange or flashing portion projecting outwardly from the curb portion. In one embodiment, the curb portion has a peripheral rim surface and a lower step surface, and an upper pane of glass or plastic has a peripheral portion attached or sealed to the rim surface. In another embodiment, the curb portion is inclined and integrally connects the flashing portion to a top glazing panel. Additional panes of plastic sheets may be attached or sealed to the peripheral portion of the upper pane and/or to the step surface and/or the flashing portion to provide increased thermal insulation. Parallel ribs are formed in the flashing portion, and rigid or aluminum trim members form a decorative frame around the skylight pane and curb portion. Strips of rigid plastic insulation foam and wood trim may be bonded by adhesive to each other and to the inner surfaces of the curb portion.