Roof Shape
A roof can have more than one function that is to shelter one from the weather.
Our ancestors created their roof with meaning that they can be associated with in mind.
Let's look at the Minangkabau roof.
(Source: Rumah Gadang - Wikipedia)
The curvature and the ornament at the tip of the gable were not shaped by the physical environmental factor but belief, history, and culture that defines the historical-contemporary aesthetic at their time.
Now, look at House VI by architect Peter Eisenman.
You do not really observe the roof in your visual priority but the other relationship between the external elements from the outside before you enters the house.
The fact that the form of the roof is not noticeable (blend with other visual elements in an abstract manner) is also one function of the roof.
Then, look at Itsukushima Shrine.
(Source: Itsukushima Shrine - Wikipedia)
We do not call the shrine a house but it works more like a gateway and a structural symbolism for reminiscent and worshipping (now place for a social media pilgrimage - a place to “check-in” using a smartphone app).
And the significance here is that the structure has an element that looks like a roof but it does not shelter like a house roof.
Apart from these significances, a roof can:-
*Shade you from the unwanted hot sun
*Invites pleasant sunlight and daylight into the space underneath the roof (indoor and outdoor)
*Shelter you from unwanted rain
*Gives you enclosure
*Serve as access, or a platform to stand on (for star gazing, view-out, or feel outdoor)
Define its use, so, you can decide on:
*the thermal mass of the roof material
*the depth of the roof eaves, opening at your roofs, and the material of the roof openings
*the area of the roof covering
*the shape of the roof and the form of spaces that it can shape internally and externally
*the type of roof
(For more info on the suitable roof design for the climate, read roof design for the hot and humid climate.)