Life cycle assessment of timber components in Taiwan traditional temples

For years, research on the life cycle of conventional building materials (e.g. reinforced concrete and metal structures) has been studied; however very little literature can be found in non-conventional materials such as timber. Ever since the 1999 Chi-Chi earthquake that happened in Taiwan, many traditional timber framework buildings were destroyed or severely damaged. For the past decade, enormous amount of resources have been invested by the Taiwanese government to begin various studies on traditional timber building techniques, timber material testing etc. Although correct building technique or proper use of building material are crucial towards establishing a structurally-sound timber framework, without proper building maintenance, the structural integrity will also be jeopardised in future. With the continual decline of timber supply, re-using existing timber materials becomes especially important in building conservation. In this paper, eight Taiwanese traditional temples are used to study the life cycle of historic timber framework. Based on past records of each building's restoration process, statistical calculations of various timber components at different repair stages and oral interviews with the traditional master carpenters, architects and timber surveying units, results shown that alteration design during repair stage is recommended as it enables architects to give more informed repair advice. However if improper or unsuitable measures are carried out during emergency rescue work, timber deterioration will only aggravate further instead of being salvaged. Lastly, a theoretical calculation method for timber framework life span is proposed by using 50% as the critical point for overall structural failure.