A skillion roof includes a single slope, like a shed or slant roof, and there is no lodged at the roofline. The result is walls of varying heights within the construction. Combining a skillion roof with a lean-to roof is a contemporary look, leading to interesting crisscrossing angles and developing a fantastic space for clerestory windows.
The vertical space that is created as a consequence of the two jutting roof angles is the best spot for clerestory windows.
Nick Deaver Architect
There is no ridge with a skillion and lean-to roof. Visual interest comes from the juxtaposition of the separate planes of the roof angles.
DOWN to Earth Architects
Skillion roofs can be assembled quickly, easily and inexpensively. The steep pitch allows water to run off easily and reduces the need for the extra waterproof roof membranes which lower-pitched roofs require. The steeper pitch also adds itself to a contemporary layout, and the substances utilized for a skillion roof, like metal, are inclined to be slick, unlike the tiles or shingles of a classic gable or hip roof.