Towards the Understanding of Embodied Energy in Buildings: Emergy of Construction and Demolition

Abstract

This paper presents the study of embodied energy use throughout the construction and demolition as a tool to indicate embodied energy efficiency and environmental inputs of buildings and building materials in Thailand. Emergy 26 Journal of Architectural Research and Studies Volume 2 2004 Faculty of Architecture Thammasat University Analysis Technique is used to calculate the amount of energy required to make something expressed in units of the same form of energy, called Solar Emergy. And Emergy of money, called Embath has also been evaluated. The objectives are to evaluate and compare Emergy and Embath of buildings to help determining the Emergy saving and the environment benefits of buildings and building materials during construction and demolition. The method is to collect and analyze data inputs of cost and quantity from bill of quantity; BOQ of buildings: residences, schools, offices and hospitals for construction and 2 types of structure, halftimber and concrete structure for demolition. Materials during construction and demolition of each building are evaluated. This study examines all factors, which are Emergy, masses and cost, and environmental inputs to create Emergy index and environmental index as well. Four influencing factors effecting Emergy values are found: Renewable resource or structure, non-renewable resource or decoration, building system and labor. Structure is the major factor of residential buildings, schools and office buildings. Decoration is the major factor of hospital buildings. In demolition stage, structure is also the main factor. In demolition stage, Emergy value of half-timber structure buildings is the same as 7 years of energy consumption. Whereas Emergy value of concrete structure building is the same as 19-30 years of energy consumption. Therefore, structure materials should be used in as small amount as possible, especially the high transformity materials. Eventually, the environmental index suggested that using more renewable than non-renewable resource would be appropriate to the environment and the world resource. The building usable life is depend on materials, the more non-renewable resource, the longer life of the materials should be used.