Earthquake resistant houses

Most home builders in Manokwari city of West Papua must take into account earthquake resistant structures when constructing houses. The use of steel profiles or steel rods for pillars for multi-story buildings is highly recommended. Although metal buildings are strong and suitable for earthquake region, they are not fully popular due to aesthetics consideration. Home owners in Indonesia still prefer wooden framed houses with concrete walls as the most affordable and beautiful constructions.  The department of public works (called DPU or Departement Pekerjaan Umum) stipulate that all houses with two floors and above must have structural strength calculations done by architects and civil engineers who design the buildings when submitting their works to the department for obtaining their approval.

For small one floor homes, the use of hard wood for house frames is a common practice in this city. To hold the concrete walls, the construction workers hammer big nails along the wooden pillars and girders along the sides where the bricks of the concrete walls will be built. When earthquake hits the city, these nails will hold the walls from falling onto the ground and hit the occupants of the houses. The distance of the pillars has also been reduced to a maximum of 4 meters for family homes with two or three bedrooms.

Building materials for the foundation of the houses are granite stones or hard corals that are mined from the mountains. The mining of corals from the coastal area has been banned due to its destructive impact on the marine environment.

Although Papua is rich of timber, some home buyers in Manokwari still orders prefab building or wooden houses from Woloan village in North Sulawesi. These earthquake resistant wooden house of Minahasa, after being dismantled and shipped to Papua, will be reassembled and constructed on sites that have been cleared for them.

For Papua and Indonesian islands in general, wooden houses or concrete houses whose pillars are made of wood are the most recommended constructions. The use of wood is cheaper than steel frames. To prevent the wooden blocks and planks from deteriorating or decaying due to the changing weather, anti termite and base paints have to be applied on their surfaces. These kind of coatings will protect the wood for tens or even hundreds of years to come.

I used to study Archicad, a BIM modeling software for architects and home designers. This is a very powerful software for designing homes and big buildings. Although it has the ability of calculating the number of materials needed by the designed houses, it lacks features for strength calculation that is very important for houses that will be built in earthquake region such as Indonesia. Architects still need other software such as SAP 2000 to do the structural strength analysis. by Charles Roring

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Wooden houses near the beach of the Dorey bay

While I was traveling to Numfor island with a ferry boat, from the sea, I saw rows of wooden houses constructed along the beach up to a slope in the Dorey bay of Manokwari city. These type of wood construction is common in this region because wood is more durable in withstanding strong earthquake. Wooden houses of the Papuan tribes in coastal region are different from the ones that I usually see in the mountainous region of West Papua. Houses that are built near the sea often have pillars that stand from the bottom of the beach to two meters above the sea surface to allow for space for high tide. The wood that are used for the house pillars have been chosen from the species that will not easily rot when soaked in the salty water for longer time.

In recent years, some Minahasan people from Woloan village migrated to Papua and introduced prefabricated wooden houses that can be dismantled from the place where it was first constructed and displayed and reassembled in a new place for the new owner of the house. Although timber as the construction material of the house is abundant in this city, the Minahasan type of the wooden houses cannot easily penetrate the local market that has already had its own indigenous model which is Rumah Kaki Seribu or "a thousand leg house" which is the typical wooden house from Arfak mountains. 

The wooden houses made by carpenters from Woloan who have now lived in Manokwari are more modern and fine in their fabrication. The carpenters use modern machine to make blocks and panels of wood that will form the house.

The big earthquake that hit Manokwari city in 2008 had reminded the city dwellers that having houses with wooden frames is more safe that building houses only with concrete materials. I personally believe that wooden houses whether they are traditional or modern in design will always be attractive in Papua because of the frequent earthquakes that hit the island. 

Tens of years ago, the roofs of the wooden houses in Indonesia were from palm leaves. These materials had to be replaced every two years. In addition, they were not fully watertight. With the improvement in the home building technology in Indonesia and the availability of more durable materials, now most of the wooden houses have been protected by corrugated metal roofs that can withstand rain and sunlight for tens of years. by Charles Roring

Also read: 

• Earthquake resistant wooden house of Minahasa


• Wooden house and alleyway of Kyoto


• How to design roof with Archicad


• How to add column and beam to a house in Archicad


• Creating a rounded corner wall with Archicad 12