The Secrets of Rumah Gadang Architecture's Earthquake Resistance

Rumah Gadang, the traditional dwelling of the Minangkabau people in West Sumatra, is not only visually striking but also known for its strong resilience against earthquakes. Behind its distinctive appearance, this traditional house is designed with physics principles in mind to maintain structural balance and strength. According to the book “The Wonder of Rumah Gadang Architecture” by Chandra Okta Fiandi, one of the main unique features lies in its foundation system. Unlike modern buildings, Rumah Gadang does not use foundations that are buried or poured with cement. Instead, the structure rests on stones placed directly on the ground surface. This method keeps the building stable. The heavy weight of the house presses down on the foundation stones, making their position firm, even without being embedded in the soil. The geographical conditions of West Sumatra, which lies in an earthquake-prone area, also influence the design of Rumah Gadang. The building structure is made more flexible to adapt to ground vibrations. During an earthquake, the wooden pillars can move following the jolts, so they are not easily cracked or broken. This flexibility is what makes Rumah Gadang relatively more resistant to earthquake damage. Not only the lower part, but the strength of Rumah Gadang is also supported by its roof design. Traditionally, the roof is made from ijuk from aren trees, arranged to taper sharply at the peak. Conversely, if the roof angle is made flatter, water could be retained longer and seep inside. This is due to the porous nature of ijuk, which easily absorbs water. The roof’s function does not stop there. Its tall design also helps smooth air circulation inside the house. The empty space under the roof acts as a heat barrier, keeping the indoor temperature comfortable even when the outside weather is hot. The ijuk material used is known to be lightweight yet strong. This combination allows the roof to be formed high without adding excessive load to the building structure.