A tool for assessing life cycle CO2 emissions of buildings in Sri Lanka

The critical role of buildings in overcoming global environmental challenges is evident from their high contribution to global energy use and carbon dioxide (CO2) emission. This study was aimed at developing a life cycle CO2 emission estimator tool for buildings in Sri Lanka. First, system requirements and system boundary were identified. Then CO2 emission calculation method for each life cycle stage was established, which was followed by development of building life cycle CO2 emission database and program. The applicability of developed tool was evaluated by a case study of a multi-storey building in Sri Lanka. In the case study, operation and maintenance stage contributed to 55.47% of life cycle CO2 emission, which was followed by material production stage (42.09%). Ready-mixed concrete, reinforcement steel, cement and clay bricks contributed to nearly 90% of CO2 emission at material production stage. To the best of our knowledge, this study is the first-ever attempt at developing a building life cycle CO2 emission estimator tool for Sri Lanka. The limited availability of local data for some life cycle stages was the main challenge faced by researchers, as national data inventories for building life cycle CO2 emissions are still not fully developed in Sri Lanka. The tool can be used to compare life cycle CO2 emissions of different buildings as well as providing means of assessing compliance of life cycle CO2 emissions of buildings to CO2 emission standards specified by green building certification bodies in Sri Lanka, thus promoting sustainable construction practices in the country.