Heian kento 1200 – Revaluation of kyo-machiya

Heian kento 1200 – Revaluation of kyo-machiya

Previously the imperial city of Japan for more than one thousand years, Kyoto is extremely  rich in cultural heritage, which was even acknowledged by the US army during the World War Ⅱ and spared Kyoto from the bombs. However, the historic townscape of Kyoto is still severely destructed, not because of the war of natural disasters, but out of the reckless development during the economic bubble. (Figure1) Apart from making ways for the construction of modern manshons, as has been mentioned in another post, the other reason for kyo-machiyas’ extinction is the underestimation of its value, functionally and culturally. Fortunately, in response to Heian Kendo 1200’s theme of「伝統と創生」“Tradition and Revitalization”, the public and government started to reevaluate the kyo-machiya.

Before 1990s, kyo-machiyas’ ability to resist earthquake was substantially underestimated. In a country prone to earthquakes, it is reasonable that safety standards for houses are much demanding. The Building Standards Law in early 1990s inordinately stipulated that diagonal bracing and strong load bearing walls, which was rigidly connected to the foundation, are obligatory.[1] The legislation imposed uniformity in all cases without special considerations for the unique structure of kyo-machiyas. The structural framework of the kyo-machiya is composed of quadrangular posts (hashira) and penetrating beams (hari), which are set on foundations directly. The mud walls are only supposed to stabilize the structure instead of bearing the load. Although being banned by the law, the performance of the structure was proved to be quite excellent in 1999 by earthquake-resistance experiments. (Figure2) It was suggested that the low rigidity is on purpose to increase the flexibility, which prevents the structure from collapse in short-wave earthquakes. And in long-wave earthquakes, the structure will just tilt a bit, which could even be pulled back to the foundation stones afterwards. With accessory assembled dampers, the traditional construction method could meet the safety standard. [2]

What was also underestimated was the fire-resistance of the kyo-machiyas. With the Tokyo firestorm in memory, In the early 1990s, the construction regulations of the Fire Services Law banned the unplastered wooden surfaces in the “fire prevention area”, which covered most of the area of the historical district.[3] However, the fire-resistance experiments since 1999 suggested that the kyo-machiyas under maintenance were not that flammable.[4] (Figure3)

Affected by the reflection about the kyo-machiya after the Heian kendo 1200, kyo-machiyas’ excellent performance in earthquake and fire resistance was acknowledged and the previous law was abolished by the Ministry of Land, Infrastructure and Transport in 2004. [5]

The cultural value of kyo-machiya was also revaluated in the late 1990s and a machiya boom was observed. Instead of considering kyo-machiya as dirty and outdated, public started to cherish the sense of community and the enjoyable nature of traditional houses, which will be further illustrated in next post.

[1] 諸星智章, & 加藤仁美. 建築基準法・都市計画法における絶対高さ規制の変遷に関する研究. 都市計画論文集, 40 (2005) :265-270.

[2] 鈴木祥之, & 中治弘行. 木造住宅土塗り壁の実大実験による耐震性能の再検討. 日本建築学会構造系論文集, 64 (1999) : 115-122.

[3] Miyake, Yuhei. “Modern Kyo Machiya: Livable Architecture for Kyoto.” (2011).

[4] 京都市木造住宅振興支援事業. 平成14年度京町家の土壁防火実験

[5] White, Bruce. “Tradition, Democracy and the Townscape of Kyoto: Claiming a Right to the Past.” Social Science Japan Journal 16, no. 2 (2013): 318-20.

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