**4.4 Ratiang Banua**

This portion of the dwelling consists of the roof, which covers the building. The Rattiang Banua structurally consists of the roof itself as well as a series of pillars and beams, which are connected through joints, notches, pins, and holes. The weight of the Rattiang Banua is carried downward to the ground by the Kale Banua and the Sulluk Banua (see **Figure 5**).

Structurally, Torajan buildings employ the tongkonan system wherein the above three elements are combined to create a single whole. This provides a strong and stable structure, one that responds positively to natural disasters (see **Figure 6**).

To understand the significance of architecture is to understand the language of its form, that is, its visual appearance. Visual and spatial aspects include the following:

	- a.Axis and balance, which indicate that the language of society may be realized through proportional and geometrically balanced dwellings.
	- b.Ground, which indicates that local society is capable of anticipating threats from wild animals and earthquakes by using stilts.
	- c.Orientation, which indicates that society is capable of realizing a sustainable design by using sun and wind energy.
	- a.Alignment; the settlements of Torajan society are aligned to form lines. This indicates the hierarchy that exists within society.

*Understanding Local Architectural Forms as a Sustainable Design Transformation DOI: http://dx.doi.org/10.5772/intechopen.109560*

**Figure 5.** *Ratiang Banua (source: riaridwana, 2020).*

#### **Figure 6.**

*Vertical spatial structure of Rumah Tongkonan (Source: oktawati, 2017) [17].*

