Problem
What kind of roof plan is organically related to the nature of your building?
Solution
Arrange the roofs so that each distinct roof corresponds to an identifiable social entity in the building or building complex. Place the largest roofs—those which are highest and have the largest span—over the largest and most important and most communal spaces; build the lesser roofs off these largest and highest roofs, in the form of half-vaults and sheds over alcoves and thick walls.
Related Patterns
… assume now that you have a rough plan, to scale, for each floor of the building. In this case you already know roughly how the roofs will go, from Cascade of Roofs (116) and Sheltering Roof (117); and you know exactly where the roof is flat to form roof gardens next to rooms at different floors - Roof Garden (118). This pattern shows you how to get a detailed roof plan for the building, which helps those patterns come to life, for any plan which you have drawn.
You can build all these roofs, and the connections between them, by following the instructions for roof vaults - Roof Vaults (220). When a wing ends in the open, leave the gable end at full height; when a wing ends in a courtyard, hip the gable, so that the horizontal roof edge makes the courtyard like a room - Courtyards Which Live (115).
Treat the smallest shed roofs, which cover thick walls and alcoves, as buttresses, and build them to help take the horizontal thrust from floor vaults and higher roof vaults - Thickening the Outer Walls (211) …
Alexander, Christopher. A Pattern Language: Towns, Buildings, Construction. Oxford University Press, 1977, p. 970.