Omo Sebua

The Omo sebua is a traditional house style from Nias island, Indonesia. They are built only for the houses of village's chiefs. Situated in the centre of a village, omo sebua are built on massive ironwood piles and have towering roofs. The houses' sole access is through a narrow staircase with a small trap door above. The steeply pitched roofs can reach 16 metres (50 feet) in height. Apart from a strong defense against enemies, omo sebua have proven earthquake resistance.

Nias is a rugged island 140 km off the mainland port of Sibolga at the western coast of Sumatra, separated by the Mentawai Strait. Nias is part of the North Sumatra province with Gunungsitoli as its administrative center. The island covers an area of 4,771 km²; the largest of its 131 chain of islands parallel to the Sumatran coast. Once a megalithic head-hunting society, its economy was based on agriculture and pig-rearing, and was supplemented by export of captured slaves in inter-village warfare. Niassan society is highly stratified and chiefs, particularly in the south of island, had access to a wealth of material resources and human labor. It was with this wealth that the early twentieth century saw the chiefs of the isolated island build themselves the grand omo sebua.

Omo sebua, or chief's houses, are situated in the centre of the village and are built on massive ironwood piles and have towering roofs. The piles rest on large stone slabs and diagonal beams of the similar dimension and material providing longitudinal and lateral bracing, enhancing flexibility and stability in earthquakes. The warring culture built them to intimidate with size and the houses are virtually impregnable to attack with only a small trap door above a narrow staircase for access. The steeply pitched roofs reach heights of 16 metres (50 feet); gables project dramatically at both the front and rear, providing both shade and shelter from tropical rains, and giving the building a hooded, towering appearance. With structural members slotted together rather than nailed or bound, the structures have a proven earthquake resistance.
Like the omo sebua, commoners' homes are rectangular in plan. The internal timbers often feature bas-relief carvings of ancestors, jewelry, animals, fish and boats with a balance of male and female elements that is essential for Niassan concepts of cosmic harmony. The more opulent houses are further decorated with freestanding wooden carvings and the internally exposed rafters are adorned with jaw bones from pigs that were sacrificed for the workers' feast at the time of the houses' completion