Omo

South Nias, North Sumatra

An omo is the house of the Nias people, and what is modelled here is the South Nias form: standing high on posts, with an open understorey full of leaning timbers, a body whose walls lean outward, and a roof far larger than the house beneath it. What makes it worth building here is not its shape but the reason for that shape — South Nias sits on an active plate margin, and the diagonal frame in its understorey is what lets the house survive shaking. It is the only house in this project whose governing rule comes from the ground rather than from people. The parts named on this screen — omo, omo sebua, ehomo, driwa, behu, si’ulu — are Nias words; where the author is not confident, the part is named in Indonesian. The sun in this model is computed for South Nias, 0.58° N and 97.79° E.

This model is one house the rules permit, not a particular house. Bawömataluo and the other South Nias villages hold houses of which no two are identical, and a chief’s omo sebua is a building of its own, far more elaborate than what is modelled here. Two things to state outright. The member sizes are the author’s estimate: the triangulation check tests the geometry, never the strength, and never will — this project has no material properties. And there is no carving at all, as with the bale; Nias houses are carved, so its absence is a real omission, but inventing motifs belonging to particular carvers would be worse than showing none.