Rumah adat are traditional houses built in any of the vernacular architecture styles of Indonesia.
Ethnic groups in Indonesia are often associated with their own distinctive form of rumah adat. The houses are at the centre of a web of customs, social relations, traditional laws, taboos, myths and religions that bind the villagers together. The house provides the main focus for the family and its community, and is the point of departure for many activities of its residents. Villagers build their own homes, or a community pools its resources for a structure built under the direction of a master builder or carpenter.
The vast majority of Indonesians no longer live in rumah adat, and the numbers have declined rapidly due to economic, technological, and social changes.
With few exceptions, the peoples of the Indonesian archipelago share a common Austronesian ancestry (originating in Taiwan, c. 6,000 years ago), and traditional homes of Indonesia share a number of characteristics such as timber construction, varied and elaborate roof structures. The earliest Austronesian structures were communal longhouses on stilts, with steep sloping roofs and heavy gables, as seen in the Batak rumah adat and the Torajan Tongkonan. Variations on the communal longhouse principle are found among the Dayak people of Borneo, as well as the Mentawai people.
The norm is for a post, beam and lintel structural system that take load straight to the ground with either wooden or bamboo walls that are non-load bearing. Traditionally, rather than nails, mortis and tenon joints and wooden pegs are used. Natural materials - timber, bamboo, thatch and fibre - make up rumah adat. Hardwood is generally used for piles and a combination of soft and hard wood is used for the house's upper non-load bearing walls, and are often made of lighter wood or thatch. The thatch material can be coconut and sugar palm leaves, alang alang grass and rice straw.
Traditional dwellings have developed to respond to natural environmental conditions, particularly Indonesia's hot and wet monsoon climate. As is common throughout South East Asia and the South West Pacific, most rumah adat are built on stilts, with the exception of Java and Bali. Building houses off the ground on stilts serve a number of purposes: it allows breezes to moderate the hot tropical temperatures; it elevates the dwelling above stormwater runoff and mud; it allows houses to be built on rivers and wetland margins; it keeps people, goods and food from dampness and moisture; lifts living quarters above malaria-carrying mosquitos; and reduces the risk of dry rot and termites. The sharply inclined roof allows the heavy tropical rain to quickly sheet off, and large overhanging eaves keep water out of the house and provide shade in the heat. In hot and humid low-lying coastal regions, homes can have many windows providing good cross-ventilation, whereas in cooler mountainous interior areas, homes often have a vast roof and few windows.
Examples of rumah adat include:
- Batak architecture (North Sumatra) includes the boat-shaped jabu homes of the Toba Batak people, with dominating carved gables and dramatic oversized roof, and are based on an ancient model.
- The Minangkabau of West Sumatra build the rumah gadang, distinctive for their multiple gables with dramatically upsweeping ridge ends.
- The homes of Nias peoples include the omo sebua chiefs' houses built on massive ironwood pillars with towering roofs. Not only are they almost impregnable to attack in former tribal warfare, but flexible nail-less construction provide proven earthquake durability.
- Rumah Melayu Malay traditional houses built on stilts of Sumatra, Borneo and Malay Peninsula.
- The Riau region is characterised by villages built on stilts over waterways.
- Unlike most South East Asian vernacular homes, Javanese joglo are not built on piles, and have become the Indonesian vernacular style most influenced by European architectural elements.
- The Bubungan Tinggi, with their steeply pitched roofs, are the large homes of Banjarese royalty and aristocrats in South Kalimantan.
- Traditional Balinese homes are a collection of individual, largely open structures (including separate structures for the kitchen, sleeping areas, bathing areas and shrine) within a high-walled garden compound.
- The Sasak people of Lombok build lumbung, pile-built bonnet-roofed rice barns, that are often more distinctive and elaborate than their houses (see Sasak architecture).
- Dayak people traditionally live in communal longhouses that are built on piles. The houses can exceed 300 m in length, in some cases forming a whole village.
- The Toraja of the Sulawesi highlands are renowned for their tongkonan, houses built on piles and dwarfed by massive exaggerated-pitch saddle roofs.
- Rumah adat on Sumba have distinctive thatched "high hat" roofs and are wrapped with sheltered verandahs.
- The Papuan Dani traditionally live in small family compounds composed of several circular huts known as honay with thatched dome roofs.
The numbers of rumah adat are decreasing across Indonesia. This trend dates from the colonial period, with the Dutch generally viewing traditional architecture as unhygienic, with big roofs that sheltered rats. Multi-family homes were viewed with suspicion by religious authorities, as were those aspects of the rumah adat linked to traditional belief. In parts of the Indies, colonial authorities embarked on vigorous demolition programmes, replacing traditional homes with houses built using Western construction techniques, such as bricks and corrugated iron roofs, fitting sanitary facilities and better ventilation. Traditional craftsmen were retrained in Western building techniques. Since independence, the Indonesian government has continued to promote the 'rumah sehat sederhana' ('simple healthy home') over the rumah adat.
Exposure to the market economy made the construction of labour-intensive rumah adat, such as the Batak house, extremely expensive (previously villages would work together to construct new homes) to build and maintain. In addition, deforestation and population growth meant that the hardwoods were no longer a free resource to be gathered as needed from nearby forests, but instead a too-expensive commodity. Combined with a general appetite for modernity, the great majority of Indonesians now dwell in generic modern buildings rather than traditional rumah adat.
In areas with many tourists, such as the Tanah Toraja, rumah adat are preserved as a spectacle for tourists, their former residents living elsewhere, with design elements exaggerated to the point that these rumah adat are considerably less comfortable than the original designs. While in most areas rumah adat have been abandoned, in a few remote areas they are still current, and in other areas buildings in the style of the rumah adat are maintained for ceremonial purposes, as museums or for official buildings. Buildings are sometimes built with modern construction techniques that include stylistic elements from rumah adat, such as The House of the Five Senses in the Efteling, a building modeled on the Minangkabau rumah gadang. In the colonial period some Europeans constructed homes according to hybrid Western-adat designs, such as Bendegom, who built a 'transitional' Western-Batak Karo house.
It has been noted that the traditional wooden houses are generally more earthquake-resistant than modern brick designs, although they are more vulnerable to fire. In some areas, a 'semi-modern' rumah adat concept has been adopted, such as among some Ngada people, with traditional elements placed inside a concrete shell.
- Dawson (1994), p. 10
- Dawson (1994), p. 8
- The Oxford Companion to Architecture, Volume 1, p. 462.
- Dawson (1994), p. 12
- Dawson (1994), pp. 10-11
- Dawson (1994), p. 11
- Nas, p. 348
- Nas, p. 347
- Transformation of Building Form: Development of Traditional Dwelling of the Ngada, Central Flores Island - Toga H Pandjaitan
- Nas, p. 352
- Nas, p.349
- Dawson, B., Gillow, J., The Traditional Architecture of Indonesia, 1994 Thames and Hudson Ltd, London, ISBN 0-500-34132-X
- Schoppert, P., Damais, S., Java Style, 1997, Didier Millet, Paris, 207 pages, ISBN 962-593-232-1
- Wijaya, M., Architecture of Bali: A source book of traditional and modern forms, 2002 Archipelago Press, Singapore, 224 pages, ISBN 981-4068-25-X
- Peter JM. Nas, The House in Indonesia