Define the roof before choosing the covering
Start with the roof shape, measured slopes, existing deck and the locations of chimneys, walls, skylights and lower roof sections. An attractive material still needs a compatible design at every transition. Ask whether one covering can appropriately serve the whole building or whether a separate system is needed for a lower-slope addition.
Write down your priorities in order. These might include maintaining a familiar appearance, reducing the number of future interventions, accommodating planned solar equipment or coordinating with an upcoming exterior renovation. A useful comparison connects each priority to a specific assembly detail.