Roofs come in all shapes and sizes. Given the nature of roofs, there is a lot to think about when you place a roof onto your building. If it is a flat roof, pitch is definitely a consideration. Drainage to roof drains or scuppers is another consideration as well. But how about pitched roofs? Now we are in an entirely new realm of options, pitches, slopes, and everything else you can throw at a roof design. Also, there are always dormers that no pitched roof can live without! Do the dormers align with the eaves, or are they set back from the building?
Placing roofs by footprint
Creating a sloping roof
Roofs by extrusion
Adding a roof dormer
This book can't address every situation you will encounter with a roof ...