Quantitative study of life cycle carbon emissions from 7 timber buildings in China

Purpose China has proposed the carbon emission target in 2020, and timber building is one of the solutions to reduce carbon emission in building sector. This study conducts a comparative study to quantitative analysis of the decarbonization potential of timber buildings from a life cycle perspective. Methods Seven representative demonstration projects with a timber structure in China were selected as research objects. The materials inventory was collected. Based on China’s national standard Standard for Building Carbon Emission Calculation (GB/T51366-2019), the life cycle carbon emissions from all 5 stages, including production, transportation, construction, operation, and demolition stages, are calculated. The assessment results are compared to ordinary reinforced concrete buildings and ultra-low energy buildings. Results and discussion The findings indicated that carbon emissions in the operation stage of buildings accounted for an average of 87.7% of carbon emission in the total life-cycle of buildings. Compared to ordinary buildings made of reinforced concrete, timber buildings can reduce carbon emissions in the production stage by 64.5%. Therefore, from a life-cycle perspective, 11.0% of carbon emissions can be saved. By upgrading energy efficiency to ultra-low energy buildings, although the carbon emission from building material may increase by 28.5%, the carbon emission is significantly reduced by 39.3% during the operation stage, with a 32.7% reduction for the life cycle. Conclusions This study provides a life cycle assessment of carbon emission of 7 timber buildings in China. The timber buildings only contribute to the decarbonization for the production stage. Around 11.0% of carbon emissions can be saved for timber structures. Meanwhile, 32.7% more carbon emissions can be saved by upgrading the energy efficiency to ultra-low energy buildings. This study also shows LCA is an effective tool for evaluating the contributions of different aspects and to ensure the achievement of carbon emission targets.