Animate timbers.

The Batak, Minangkabau and Nias peoples inhabit the western edge of the 3000 mile long Indonesian archipelago. Hidden in Sumatra's vast volcanic landscapes their traditional timber architecture adapts and survives, rooted in local culture and place. It is a powerful statement of ethnic identity in this time of rapid Indonesianisation.(1) But, as the forces of change grow ever more insistent, it seems important to document this unique architectures. What follows is a description of four houses from four regions of Sumatra.

BATAK: House of Opu Duma Sitorus Manurung, Lumban Binanga, North Sumatra 

Most Batak are ostensibly Christian now but traces of animism remain, rooted in the awesome natural spectacle of their heartland around Lake Toba with its smoking craters, blazing sunsets and violent storms.

Approaching Lumban Binanga through smouldering terraces of stubble, the first sign of settlement is the saddle-shaped ijuk (palm-fibre) roofs soaring over mud and bamboo ramparts. Central to the village is a space of bare earth, shaded on one side by the outward-leaning gables of the rumah adat (traditional houses). When rice was stored communally two sopos (rice barns) were located on the other side. One of these has now been converted to a dwelling, the other replaced by a small chapel.

Opu Duma's rumah adat was built five generations ago. The three others were built as the Manurung family grew. Originally it accommodated 10 people in a single large space. The head of the household slept at the back right of the space, where the densest, best quality timber is used. The door and partitioned space to the right of it are new additions, replacing a trap door entrance. During festivities music is performed on the galleries inside and outside the facade. A buffalo, which Opu Duma shares with a family in the neighbouring village, is stabled beneath the house.

The structure consists of two rows of four piers (preserved by being soaked in mud prior to construction) carrying longitudinal beams from which the ends of the rafters are suspended, thus allowing the roof to settle into position. This flexible connection is perhaps a means of withstanding earthquakes, It also removes all load from the side walls which can be taken away to provide extra light, yet curiously the non-loadbearing edge beam at floor level is still extremely large and heavy. This beam is terminated on the facade with a carving of a lion's head to ward off evil spirits. Other decorations, painted in traditional red, white and black, includes breasts (in groups of four) for fertility, aeroplanes and buffalos. Indeed the entire form of the house is said to represent the buffalo and in some other Batak villages real horns are mounted on the peak of the front gable.

MINANGKABAU: Semsinah's House, Balimbing, West Sumatra 

Minangkabau means 'victorious buffalo' in celebration of a legendary buffalo fight which saved the people of the Western Highlands from Javanese domination. Buffalo horns are represented in the delicate, soaring roofs of the longhouses (rumah gadang) and in the formal headwear of the women.

Minangkabau people belong to clans falling into two groups: Koto Pilang (autocratic) and Bodi Caniago (democratic). Members of both groups have always lived in the village of Balimbing. Koto Pilang houses and meeting halls are distinguished by their raised ends that accommodate a hierarchical power structure while Bodi Caniago houses, like that belongings to Semsinah, have level living platforms.

Traditional Minangkabau society is both Islamic and matriarchal and today ancestral property is still passed down the female line. Positions of religious and secular power are occupied by men in accordance with Islamic convention, but the family is organised around the women and in this the rumah gadang plays a defining role. A married man might sleep at the house of his wife in her small 'daughter's room' but will always belong to the house of his mother, working to further its prosperity and taking responsibility for the upbringing of the children of his sisters.(2) Semsinah's house, now occupied due to its dilapidated state, was home to four families descended from a common great grandmother. This is evident in the way in which the four pairs of bays in the main front space appear to have been separately embellished over time. The elders slept in this room and guests were received here. The end walls of woven bamboo admit a soft light and allow cross-ventilation. Goats and a buffalo are stabled underneath.

NORTH NIAS: House of Bapak Aluizatulo Larosa, Dahana, North Nias Island

The small island of Nias is located off the west coast of Sumatra, pounded by surf from the Indian Ocean which stretches from its shores uninterrupted as far as Antarctica and Africa. The earliest settlements were in the centre of the island, but the communities which moved north and south have evolved in different ways. Those in the north are small, numerous and closely related because traditionally power descended directly from the founding father, encouraging young men to leave the village of their birth to found new ones.

The village of Dahana sits on a hilltop with views out to sea. With neighbouring Hilibawadesolo and Hele Fanikha, it is occupied by a single family, the Larosas. Aluizatulo Larosa claims that his house, the largest of the five in the village, is 200 years old although much of the timber has been renewed, sometimes recycling parts from other houses. In front of it is a raised area of weeded ground on which stand some megaliths. Some of these commemorate feasts (and so showed family status) while others had religious or judicial functions.

The living platform of the house is oval in plan and is supported on closely spaced posts which absorb the unevenness of the rocky terrain. These are diagonally braced in both directions to withstand earthquakes. It is a single volume, partitioned to a height of about two metres to provide rooms for Bapak and Ibu Larosa, their youngest children and daughters. The large front room seems to be regarded as semi public space during daylight and major village gatherings are held here including Sunday school. Within this space a small change in level defines an increase in privacy between the entry level in the centre of the plan and the social space at the front with its bench and slatted opening running the length of the elevation. Cooking takes place in an extension at the back, demanded by the Dutch colonial administration to reduce the risk of fire. Behind this, where the ground falls away, is an area for washing, the keeping of pigs and waste disposal.

SOUTH NIAS: Amos's House, Hilinawalo, South Nias Island

The villages of the south were governed democratically through a council so some degree of power and status was available to all.(3) As a result villages are fewer and much larger than those in the north and enjoy a more civic way of life. Hilinawalo, with a population of about 1500, has some public buildings: a Chief's house and meeting hall, two churches and some shops. There are also dance, music and sporting societies.

It is incredible to emerge suddenly from the jungle into the dense, urban space of a south Nias village with its long street lined with galleon-like facades. Villages, fields and paddies are linked by a network of smooth stone paths. Such a path (iri newali), defines the right of way and continues through the centre of the street, becoming wide enough for only a single person. To each side are areas used for drying crops and clothes (and playing volleyball on Sundays). In front of the older houses are collections of stone megaliths (oli batu) behind which is a drainage culvert and finally, under the overhanging eaves, an area used for domestic duties and other work. Also in the street is a trapezoidal wall of stone, traditionally used to train young warriors to leap enemy defences but now (without the knives mounted on top) used only for sport.

Houses are paired and entered from the sides with two houses sharing one porch. The front room has doors in both side walls, deep into the plan, joining each house to its neighbours so that a continuous passage is formed running the length of the street. In some villages, this passage is patrolled at night by a fire-watchman. From this lowest, semi-public level of entry, the floor steps up 400mm to the batu - a 1.6m deep platform of removable planks with storage underneath. In Amos's house this was both the main social space and where the unmarried men slept. The next level (farakhina) is a bench from which the family watched the goings on of the street. The rest of the household slept in the back room on a similar raised level to the batu. The hearth is still in its original position beneath the ridge of the roof.

These houses, in common with Batak rumah adat, were traditionally constructed from a prescribed menu of hardwoods, each with its own physical and perhaps spiritual properties. Now these are unavailable but alternative materials are generating exciting and appropriate new developments - brightly painted facades, rusted iron in place of ijuk roofs and concrete benches in place of stone megaliths. But the older houses are especially valued, for those communities orientate themselves around the memory of their ancestors and the timbers, worn smooth by generations of use, seem to have assumed an almost animate quality.

1 Evidence of this is in the numerous new churches, mosques and tombs that incorporate entire traditional house-forms into their architecture in place of conventional religious forms.

2 Kato, Tsuyoshi 1982. Matriliny and Migration: Evolving Minangkabau Traditions in Indonesia. Cornell University Press.

3 Viaro Alain 1980. Urbanisme et Architecture Traditionnels du Sud de L'ile de Nias, Etablissements Humains et Environnement Socioculturel, UNESCO.