Forecasting embodied carbon emission: case of two-storey residential buildings in Sri Lanka

Purpose With the use of increased number of measures and strategies towards mitigating operational carbon emissions, a greater emphasis has now been placed on reducing the resultant embodied carbon (EC). However, the assessment practice seems cumbersome due to variation in data and methodologies. To this end, this study aims to develop a basis that would facilitate early-stage EC assessment for a proposed building. Design/methodology/approach This study primarily involved a quantitative analysis of 50 Bill of Quantities (BOQs) of two-story house projects. Additional information such as materials, vehicle and plant and equipment used in construction was obtained from technical specifications, industry practiced norms and databases. The EC emission was calculated using basic statistics. Findings The total EC emission in the construction of a two-storey residential building is equivalent to 0.0607 tCO2e per square feet of Gross Internal Floor Area (GIFA). Concrete is the highest contributor in the material production with 36% of emission in the production stage that is responsible for 94% of total EC. The excavation and earthwork is the highest EC emitter during the material transportation stage (93% of total EC emission in transportation stage). During the construction stage, reinforcement shows the highest emission of 85% of total EC emission in construction. The study concludes that the distribution of carbon emission among elements contributes efficient resource allocation towards achieving sustainability in buildings. Originality/value This study provides a basis to forecast the EC emitted during cradle-to-end-of-construction stage of a proposed building. From the implication perspective, it is expected that the basis which the study provides would enable to determine the appropriate carbon tax to account the potential client for his contribution to GHGs.