Rural Khmer house

The rural Khmer house is a perfect example of a dwelling whose simple structure serves its main functions. As well as providing a living and working area, the building serves as a shelter, which is of vital importance in the everyday life of a home in a rural setting that is exposed to the elements. During the day the house functions as a large umbrella. Work and life go on at ground level, where the most effective shade is provided. This area is used for eating and resting, as well as craftwork and various other tasks such as the repair of farm equipment.

As the space below the building is dry and easily accessible some less used areas at its outer limits are used for storage; for example people may collect and store wood here until they are able to build the next house for their relatives. People do not stay upstairs during the day; they only sleep here at night. A separate room beside the main living space, which is often a step lower than the upper floor, is reserved for cooking.

Typically, the kitchen is situated at the back of the house, often some steps lower and attached to the main building; it is not uncommon for there to be two entrances to this room, one from the upper floor and one directly from the ground level. Sometimes the kitchen is in a separate building near the house.

Much attention is paid to certain details, especially in a new house: the main beam of the roof and the main pillars are partially wrapped with glittering metal bands that invite good spirits to protect the house.

The typical rural house is the basic structure from which all variations have developed. Construction elements are made of wood; rounded posts are used for piles, whilst joists are made of squared beams. Simple carpentry is used to join horizontal and vertical elements; the use of screws, which would increase expense, is avoided. Panels of homemade palm matting cover the sides of the house; fixed to the wooden structure in a simple fashion they merely provide protection against the elements but have no influence on the stability of the construction. Palm matting is also used for roofing.

The house pictured here is situated in a settlement. Typical characteristics of such a settlement are: The private sphere of each household is restricted to the area occupied by their dwelling; Delimited by the stilt structure of the house, it is at ground level that daily life – work, eating and family interaction – takes place. Livestock is kept here, in simple pens. These typical wooden buildings surround an open space (approximately 150 m2), where there is a communal source of water, which forms the centre of the settlement.

The image on the right shows a 107-year-old house and is still owned by the same family. It has a wooden structure, with bamboo walls. The roof is thatched with rice straw. The lifespan of such houses is obviously not very long, probably not more than 100 – 120 years.

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  This house is 107 years old

These houses stand in water, either temporarily or permanently, and are genuine pile buildings, with no foundations. Wooden diagonal struts that strengthen the piles standing in the water ensure the stability of the building.

Modern rural houses differ from simple rural houses above all in the wall cladding and roof covering. Wood is still used for the main structure, the only difference being that the piles stand on individual prefabricated concrete foundations. Instead of the original homemade palm matting, wooden boarding is used for wall cladding. Windows and doors remain as structural openings, but sometimes they are equipped with shutters.

Clay tiles or corrugated tin roofing replace the conventional roof covering that simply provided protection against the sun. Tiles are not homemade and have to be purchased. The use of modern building materials and the consequent alteration in the basic structure of the building increases the need for ventilation.

Today's population has an ever-greater need for security and prosperity. In contemporary houses, the ground level, which was previously an open area simply defined by the open framework of the building, is now walled in. The walls are made of brick and are rendered on the outside and inside. The interior is now no longer an open space but divided into separate rooms by dividing walls. The window and door openings, so important for efficient natural ventilation, are now closed with wood-framed glass windows and a solid wooden front door.

The upper floor is still made of wood and built in the same way as the traditional wooden houses. However, the walled construction of the ground level means that the load no longer has to be conveyed to the individual points of the supporting structure, but can now be distributed at random. Consequently, we now find constructions that differ radically from the typical traditional basic design.

Colonial architecture introduced the idea of solid, durable buildings that could be bought, sold and inherited. This was a radical cultural change. Such buildings were “grounded” by a system of walls requiring foundations rather than the traditional post and beam structure made of wood and raised off the ground. The Southeast Asian tradition of carpentry uses ingenious structures that are stable with a minimum of material. Carpentry for construction derives from three-dimensional thinking from boat building, basket weaving and even kite building.[2]

While the traditional wooden house was built on stilts with matting used to enclose the raised living area, the colonial house had thick walls in which window openings could be cut out. With colonial architecture, the wall and the mason are predominant. With traditional architecture, wooden post and beam and the carpenter come into their own. This section "Masonry Versus Carpentry" is an excerpt from the book Building Cambodia: New Khmer Architecture 1953–1970.[3]

In farming communities people do not seem to be particularly concerned about health. Unless the illness is due to an eating disorder, which can be dealt with by a change in diet, it is assumed that it is caused by spirits. Due to the collective consciousness of the community, illness may affect not only individuals, but entire households and villages. When this occurs, people believe that the spirits are not taking good care of them, so they move to another house for another ‘contract’. They may even abandon a village for the same reason. For further information about household and family structures see: http://countrystudies.us/cambodia/42.htm

People in Cambodia do not have much furniture. However, one item that is found in all houses is a multifunctional low table, which is used for sleeping, sitting, talking and working. Different styles of tables are found both upstairs and downstairs – always within the area of the house itself; on the ground level it is a vital element of daily life. A hammock is used for sleeping during the daytime and is the most relaxing and comfortable piece of furniture. On the upper floor the same type of table-like furniture is used as a bed.

In more urban surroundings, people may have a simple type of sideboard on which they place items of importance: a television, a Buddha shrine, a battery operated light, mobile phones, as well as photographs of their grandparents and members of the family who have died. Because of the spatial organisation of the basic Khmer house, furniture is placed alongside the walls within the personal space of the inhabitants. The central area is always left free and is used as a common room.

The building consists of a supporting framework, which stands on individual foundations. There are no bracing or shear walls to strengthen the structure. The roof is built before wall cladding is applied.

The load-bearing piles of the building stand on single foundations. To comply with the specific conditions of the generally loamy soils, single foundations are laid in the following manner: At the bottom of a 1 metre deep excavation several wooden poles of 1.5 – 2.00 metres length are rammed into the ground and then covered with a layer of compacted stone, followed by a hewn stone or prefabricated concrete slab, which provides the base for the pile. The excavation is then filled with soil. In a modern version the single foundations are linked with concrete slabs and prefabricated pillars extending to the upper floor are used.

For each pile, a single round hardwood tree trunk, such as .(...) is used. Extending from the foundation to the roof, and in the centre as far as the roof ridge, the piles, together with the horizontal joists, form the bearing structure of the house.

Rectangular-sawn hardwood (such as ...) is used for the joists. In earlier built, traditional houses these continuous elements run through the vertical piles, whereas in more modern houses joists consist of two elements running either side of the piles.

The distance of the joists can not use for a long distance (From 2m to 3.75) for the Khmer house structure because it is easy to crack or bend while we use over load. So the technical of Khmer house almost use the wood as a principle materials.

Piles, joists and rafters, on which battens are laid, are linked together to form a rigid roof truss. This construction helps to stabilise the whole structure of the house, and can be described as a rigid prism on stilts.

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  Piles
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  Piles
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  Piles
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  Joists
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  Joists
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  Joists
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  Roof

Given the absence of diagonal bracing or shear walls, the stability of the structure depends on the joints. In traditional houses transverse and longitudinal rigidity is achieved by passing the horizontal joists through the piles, in close proximity, one above the other. Wedges are used to lock the joists in position. Nowadays this labour-intensive technique is no longer used and joists are no longer passed through the piles; instead the joists consist of two identical beams that are placed to each side of the piles, to which they are fixed by screws or nails.

Differences in the design are basically dependent on the financial means of a family and the materials available. Houses of simple farmers generally have walls made of palm leaf matting, the preparation of which is labour-intensive but does not rely on imported materials. The palm leaf matting is fixed directly to the structural framework. Fine bamboo struts are often used to anchor the matting. In more sophisticated houses wooden boards are used to clad the walls, aligned either horizontally or vertically. The horizontal version is fixed like weatherboarding, with the upper board overlapping the board below. Boards are butt jointed; in some cases joints are covered with a strip of bamboo.

Temperature and humidity recordings show that variations in temperature of the inner and outer surfaces no greater than + / - 1 °C. Thermal imaging confirms this, which leads to the conclusion that there is no noticeable difference in temperature outside or inside the house. Contrary to expectations, constant air circulation, which would have a cooling effect on surface temperatures, does not take place. However, the gap between the roof and the walls allows air to flow in and out, thereby preventing heat accumulation below the roof (see 6.3.).

Infrared thermal imaging reveals that the lowest temperatures are found at ground level beneath the house. It can be said that the comfortable indoor climate is brought about by a combination of the ‘umbrella effect’ of the roof and natural ventilation. The roof shields the house against direct heat radiation, whilst the continuous opening between the roof and the top of the walls allows a constant flow of air in and out, which prevents an accumulation of warm air beneath the roof.

Despite indoor temperatures of 36 °C and up to 80% relative humidity, and though there is no electric air-conditioning, a comfortable, draught-free environment is maintained. This is possible thanks to the ‘umbrella effect’ of the roof.