Embodied energy assessment of building structural systems using building information modeling

Abstract

As the population of the world increases, the need to develop sustainable housing has gained worldwide attention. Although buildings contribute to socio-economic development, they are also among the biggest consumers of energy and contributors to the greenhouse gas emissions. Building construction projects are typically recognized for substantial consumption of natural resources and energy consumption. The most common structural materials used in the Canadian construction industry are steel, reinforced concrete, and engineered wood. Cost, the speed of construction, and the mechanical performance have been usually the main criteria when selecting a building’s structural system, with the environmental impact of the structural material typically ignored. Environmental impact is overlooked mainly because the industry lacks a documented framework, similar to cost estimation and scheduling, for assessment. Although there are several studies that have studied energy consumption of buildings, they mostly focused on the operational energy, since it has the highest energy consumption in a building life cycle. This research project introduces a framework for the environmental assessment of structural materials, in which it calculates the embodied energy of the material production and construction as the main parameter for comparison. This assessment tool is implemented using a building information modelling platform to automate the process. This method considers all the main factors in estimation of the embodied energy, including production, transportation, installation/construction, and wastage of the material. A case study on two typical residential buildings with a similar layout but different structural systems were carried out to assess the practical use of this approach in the design stage. This system demonstrated an easy-to-use process to estimate embodied energy of the structural material using the building information model of the structure. The results indicate that the manufacturing stage has the most significant iv impact on the embodied energy and GHG emissions of the building structures. In addition, integration of the building information modeling to the assessment system could facilitate the embodied energy assessment process for decision makers.