Mansard roofs, originating from French architecture, are often considered the most complicated roof type. They feature a double slope on all four sides, with the lower slope steeper than the upper one. This design not only provides additional living or storage space in the attic but also demands skilled craftsmanship for correct construction. Its complexity lies in the intricate detailing and the challenges involved in achieving effective weatherproofing at the multiple angles and joints.

Flat roofs are typically best for green roof construction. They provide a level surface for plants and facilitate easier maintenance and irrigation. However, a slight pitch, typically no more than 30 degrees, can also work well to provide efficient water drainage, preventing waterlogging that could damage the roof structure.