Calculation of a building's life cycle carbon emissions based on Ecotect and building information modeling

Under the dual carbon goals, carbon emission reduction in the building sector has become a critical step in advancing sustainable development. As a type of intensively used public building, campus buildings significantly influence the overall carbon footprint of campuses due to their high emission profiles. This study employs building information modeling and life cycle assessment to develop a systematic life-cycle carbon emission analysis model for a university building in Hangzhou, China, covering stages from material production and construction to operation and demolition. The carbon footprint of each phase was quantitatively measured. Results indicate that the total life-cycle carbon emissions of the project reached 15,718.97 tCO2e. After accounting for a reduction of 13,11.48 tCO2e achieved through material recycling and green carbon sinks, the carbon emission intensity per unit area was 18,84.74 kgCO2e/sqm. In terms of emission distribution, the operational phase contributed 85.01 percent of the total emissions, with the heating, ventilation, and air conditioning system identified as the primary energy consumer. The material production phase accounted for 18.36 percent of emissions, largely due to the use of carbon-intensive materials such as steel and concrete. This study provides empirical data support and methodological references for the low-carbon design and management of campus buildings, facilitating the implementation of energy-saving and emission-reduction requirements in universities.

Carbon emissions from buildings account for approximately half of China's total social carbon emissions. Focusing only on the carbon emissions of building operation tends to neglect the carbon emissions of other related parts of the building sector, thus slowing down the progress of carbon peaking in the building sector. By applying life-cycle analysis to calculate carbon emissions throughout the building's life cycle, the performance of carbon emissions at each stage of building materials, construction, operation and end-of-life demolition can be identified, so that carbon reduction strategies in building design can be selected.. This paper constructed a method for calculating the carbon emissions of green buildings in whole-building life cycle, and conducted a summary analysis of the carbon emissions of 33 projects that were awarded green building certification. The study found that the Chinese Assessment Standard for Green Buildings has a significant effect on reducing the carbon emissions of buildings in whole-building life cycle. Compared with the current average operational carbon emissions of buildings in China, the carbon intensity of green public buildings is 41.43% lower under this standard and the carbon intensity of green residential buildings is 13.99% lower. A carbon correlation analysis of the provisions of the current Chinese Assessment Standard for Green Buildings was conducted, comparing the changes in the carbon intensity of buildings before and after the revision of the standards. The study concluded that the new version of the standards has a greater impact on public buildings than residential buildings, the requirement of carbon emission reduction in the production stage of building materials is strengthened in terms of carbon emission during the whole-building life cycle. This study addresses the current problem of unclear carbon emission reduction effect of green buildings.

The effect of energy saving and carbon reduction in the building industry is closely related to the realization of China’s double carbon goal. In this study, a two-dimensional framework for building life cycle carbon emissions was established, which takes into account the early stages of building design such as the feasibility study stage and scheme design stage. Taking 57 residential buildings in Xi’an City as examples, the life cycle carbon emission characteristics of residential buildings in cold areas were introduced. This study found that the life cycle carbon emission intensity is about 45~55 kgCO2/(m2·a). The operation and maintenance stage and building materials production stage accounted for the largest proportion of carbon emissions, and the sum of carbon emissions of the two stages accounted for 92.3% of the total carbon emissions. In addition, based on the probability density function, the carbon emission intensity distributions of the building life cycle, building material production stage, building material transportation stage, and operation and maintenance stage were analyzed, and it was found that each distribution fitting graph was generally in line with a lognormal distribution, and their expected value provided a reference index for carbon emission pre-assessment in the feasibility study stage. Based on the analysis and determination of 11 independent variables that affect the total carbon emissions, such as area, floor number, story height, and number of households, a multiple linear regression model for carbon emission pre-assessment in the design stage of building schemes is proposed. The R2adj of the model is 0.985 and the error is about 10%. The prediction model can provide beneficial guidance for the life cycle carbon emission prediction in the design stage of building projects, so as to reduce carbon emissions by changing building design.

Building information modelling (BIM) facilitates data collection throughout the life cycle of infrastructure, yet its implementation in life cycle assessment (LCA) for bridges poses challenges. This article presents a model that integrates BIM and LCA to assess the life cycle carbon emissions (LCCE) of bridges efficiently and accurately. The bridge’s life cycle is divided into four stages: material production, construction, operation and maintenance and demolition. Clearly defined boundaries for carbon emissions are established, and BIM generates the necessary data. A case study bridge evaluates this method, analysing factors like steel, cement and transportation using Monte Carlo simulation and sensitivity analysis. The total carbon emissions for the case bridge are 2.44 × 10^7 kg, primarily from material production and transportation (75.7%) and operation (17.6%). The study shows that integrating LCA and BIM improves carbon emission assessments, guiding low-carbon bridge choices and enhancing sustainability efforts towards carbon neutrality.

In the context of carbon peaking and carbon neutrality, the carbon emission issue in the construction sector has become increasingly salient. Campus buildings, being vital carriers of campus activities, significantly influence the sustainable development of the entire campus via their carbon emission profiles. To comprehensively evaluate the life cycle carbon emissions of typical campus public buildings, this study utilizes Building Information Models(BIM) to gather data on material and energy consumption at all stages, namely raw material procurement, construction, operation, and demolition of campus buildings. A life cycle carbon emission model for a building at a university in Hangzhou is constructed to calculate and analyze the carbon emission characteristics and intensities of each stage. The results indicate that the building in this project has a life cycle carbon emission of 15,718.97 tCO₂e. Through building material recycling and greening measures, a carbon emission reduction of 1,311.48 tCO₂e is attained. After accounting for carbon emission reduction, the life cycle carbon emission intensity of the project building is 1,884.74 kgCO₂e/m². The carbon emissions during the operation phase account for 85.01% of the total life cycle, primarily due to the high energy consumption of the HVAC system during operation. Moreover, the carbon emissions in the production stage of construction materials account for 18.36% of the total life cycle, which is mainly associated with the quantities of steel bars and concrete required for the project construction. This research offers a reference for the low-carbon development of campus buildings and facilitates the construction industry's shift towards green and low-carbon development.

Carbon emissions from bridge engineering are an important component of the carbon emissions in the construction industry. The life cycle carbon emissions (LCCE) of two commonly used simple-supported beam bridges, hollow slab bridge and T-beam bridge, are studied and compared. Firstly, in order to establish the criteria for the comparison of different bridge types, the principle of equal stiffness is proposed for the superstructures, and the principle of matching load effect with bearing capacity is proposed for the substructures. Based on the above two principles, 6 bridges of 2 types and 3 spans are designed for comparative analysis. Then, a calculation model of the LCCE of simple-supported beam bridges is established, in which four stages, production, construction, operation and demolition stages are included, and the carbon emission factors of each stage are established. Finally, the carbon emissions of 6 bridges designed above are calculated, and the main factors affecting the LCCE of simple-supported beam bridges are discussed. The calculation results show that (1) For the same span, the LCCE of T-beam bridges are about 8–10% lower than those of hollow slab bridges. The reasons for this are that T-beam bridges use 22-32% less concrete and 4.5-11.5% less reinforcement than hollow slab bridges, which reduces carbon emissions during the production and demolition stages, and that the durability of the lateral connections of T-beam bridge is better than that of hollow slab bridge, which reduces carbon emissions from the maintenance and repair of T-beam bridge in the operation stage by about 30%. (2) Carbon emissions in the production stage of simple-supported beam bridges account for 83–84% of the LCCE, 11-12.6% of the LCCE in the operation stage, 3.8–4.5% of the LCCE in the construction stage, and 1% of the LCCE in the demolition phase. Therefore, the reduction of carbon emissions is most effective in the production and operation stages of these bridges. (3) Steel and concrete are the two materials that have the greatest impact on carbon emissions of simple-supported beam bridges. 100% recycled steel can reduce the carbon emissions of bridges by 17.7 -19.2% compared with 50% recycled steel. 50% and 100% recycled coarse aggregate concrete can reduce the carbon emissions of bridges by approximately 2.9% and 5.7%, respectively. (4) The carbon emission of the superstructure of the T-beam bridge is 12.5-14.2% less than that of the hollow slab bridge in the same span, and the differences in carbon emissions of the substructures are very small due to the small differences in the loads they are subjected to. With the increase of bridge span, the carbon emission per unit area of the superstructure of simple-supported beam bridge increases, that of the substructure decreases, and that of the whole bridge decreases firstly and then increases, which makes it possible to choose appropriate bridge span to decrease the carbon emission.

The goal of double carbon reflects the new goals and requirements of China’s entry into a new development stage. In this regard, the construction industry, as a large producer of carbon emissions, should focus on emission reduction. In the whole life cycle of buildings, the carbon emission intensity in the physicochemical stage is the largest, so we should focus on the carbon emission in the physicochemical stage. Compared with the cast-in-situ concrete floor slab, the bidirectional prestressed precast hollow slab (BPPHS) has the characteristics of environment-friendly under the condition of meeting the building stress, and the manufacturing process of precast floor slab is more standardized, which can give full play to the performance of components. Based on BIM (Building Information Modeling) and LCA (Life Cycle Assessment) theory, and in the case of tram transportation, this paper studies the carbon emission of prefabricated hollow floor slab used in prefabricated buildings in the building stage. The research shows that the use of BPPHS reduces the carbon emission of 197,332.81 kg in the whole physicochemical stage, and the emission reduction rate is 46.52% compared with the cast-in-place slab. Compared with the ordinary prefabricated laminated plate, the emission reduction rate reaches 45.40%; The carbon emission sources in the materialization stage of prefabricated buildings are divided into production stage, transportation stage and construction stage. The carbon emission reduction in each stage accounts for 42.29%, 46.18% and 51.08%, respectively, in each stage of cast-in-situ floor slab. Compared with ordinary precast slab, the emission reduction rates of each stage are 34.67%, 53.60% and 47.84%, respectively. The emission reduction potential of BPPHS is very considerable. It can not only promote the development of prefabricated buildings but also have lower carbon than conventional precast slab. The study provides new ideas for reducing building carbon emissions, which will also provide reference for industry entrepreneurs and relevant governments to realize low-carbon economy and sustainable development.

In order to explore the key sources of carbon emissions and carbon emission structure in the life cycle of prefabricated concrete building, and to improve the energy-saving benefits in the life cycle of buildings. Based on the theory of life cycle assessment (LCA), the main carbon emission sources of each stage are analyzed, and the carbon emission accounting model of prefabricated concrete building materialization stage, operation and demolition stage is constructed. Taking a specific prefabricated concrete building as an example, the carbon emission composition in its life cycle is calculated. The results show that in the whole life cycle of assembled concrete buildings, the carbon emissions generated in the materialization stage account for 11.69 %, the operation and maintenance stage is as high as 88.17 %, and the demolition stage only accounts for 0.14 %. Therefore, when promoting the development of prefabricated concrete buildings, the construction industry should focus on the carbon emission reduction in the operation and maintenance stage.

Buildings produce a large amount of carbon emissions in their life cycle, which intensifies greenhouse-gas effects and has become a great threat to the survival of humans and other species. Although many previous studies shed light on the calculation of carbon emissions, a systematic analysis framework is still missing. Therefore, this study proposes an analysis framework of carbon emissions based on building information modeling (BIM) and life cycle assessment (LCA), which consists of four steps: (1) defining the boundary of carbon emissions in a life cycle; (2) establishing a carbon emission coefficients database for Chinese buildings and adopting Revit, GTJ2018, and Green Building Studio for inventory analysis; (3) calculating carbon emissions at each stage of the life cycle; and (4) explaining the calculation results of carbon emissions. The framework developed is validated using a case study of a hospital project, which is located in areas in Anhui, China with a hot summer and a cold winter. The results show that the reinforced concrete engineering contributes to the largest proportion of carbon emissions (around 49.64%) in the construction stage, and the HVAC (heating, ventilation, and air conditioning) generates the largest proportion (around 53.63%) in the operational stage. This study provides a practical reference for similar buildings in analogous areas and for additional insights on reducing carbon emissions in the future.

This study focuses on a residential project in the Haidian District of Beijing, China, employing life cycle assessment (LCA) integrated with building information modeling (BIM) to quantitatively analyze carbon emissions throughout the building life-cycle, including material production, transportation, construction, operation, demolition, and recycling. The results show that the operation and production stages are the primary sources of carbon emissions, accounting for 72.51% and 47.17%, respectively. In contrast, transportation, construction, and demolition contribute relatively minor emissions, at 3.94%, 2.08%, and 0.69%, respectively. Furthermore, renewable energy systems, building recycling, and urban green spaces as carbon sinks contribute negative emissions of −10.96%, −10.48%, and −4.95%, respectively. It should be noted that these percentages reflect the net contributions to total carbon emissions throughout the building’s life-cycle, taking into account both emission sources and sinks. As such, the inclusion of negative emissions from renewable energy systems, recycling, and urban green spaces leads to some stages having a cumulative percentage exceeding 100%. Based on these findings, this paper recommends adopting low-carbon building materials over traditional ones and widely promoting photovoltaic (PV) systems with energy storage technologies to effectively reduce carbon emissions. This study serves as a valuable reference for Beijing and other regions with similar climatic conditions, highlighting the importance of integrated emission reduction strategies to promote a green transition in the construction sector.

Comprehensive assessment of embodied environmental impacts of buildings using normalized environmental impact factors

Throughout the life cycle, the buildings emit a great deal of carbon dioxide into the atmosphere, which directly leads to aggravation in the greenhouse effect and becomes a severe threat to the environment and humans. Researchers have made numerous efforts to accurately calculate emissions to reduce the life cycle carbon emissions of residential buildings. Nevertheless, there are still difficulties in quickly estimating carbon emissions in the design stage without specific data. To fill this gap, the study, based on Life Cycle Assessment (LCA) and Building Information Modeling (BIM), proposed a quick method for estimating Building’s Life Cycle Carbon Emissions (BLCCE). Taking a hospital building in Chuzhou City, Anhui Province, China as an example, it tested its possibility to estimate BLCCE. The results manifested that: 1) the BLCCE of the project is 40,083.56 tCO2-eq, and the carbon emissions per square meter per year are 119.91 kgCO2-eq/(m2·y); 2) the stage of construction, operational and demolition account for 7.90%, 91.31%, and 0.79% of BLCCE, respectively; 3) the annual carbon emissions per square meter of hospital are apparently higher than that of villa, residence, and office building, due to larger service population, longer daily operation time, and stricter patient comfort requirements. Considering the lack of BLCCE research in Chinese hospitals, this case study will provide a valuable reference for the estimated BLCCE of hospital building.

Decarbonization potentials of the embodied energy use and operational process in buildings: A review from the life-cycle perspective

The life-cycle carbon emissions (LCCE) assessment of dairy barns is crucial for identifying low-carbon transition pathways and promoting the sustainable development of the dairy industry. We applied a life cycle assessment approach integrated with building information modeling and EnergyPlus to establish a full life cycle inventory of the material quantities and energy consumption for dairy barns. The LCCE was quantified from the production to end-of-life stages using the carbon equivalent of dairy barns (CEDB) as the functional unit, expressed in kg CO2e head−1 year−1. A carbon emission assessment model was developed based on the “building–process–energy” framework. The LCCE of the open barn and the lower profile cross-ventilated (LPCV) barn were 152 kg CO2e head−1 year−1 and 229 kg CO2e head−1 year−1, respectively. Operational carbon emissions (OCE) accounted for the largest share of LCCE, contributing 57% and 74%, respectively. For embodied carbon emissions (ECE), the production of building materials dominated, representing 91% and 87% of the ECE, respectively. Regarding carbon mitigation strategies, the use of extruded polystyrene boards reduced carbon emissions by 45.67% compared with stone wool boards and by 36% compared with polyurethane boards. Employing a manure pit emptying system reduced carbon emissions by 76% and 74% compared to manure scraping systems. Additionally, the adoption of clean electricity resulted in a 33% reduction in OCE, leading to an overall LCCE reduction of 22% for the open barn and 26% for the LPCV barn. This study introduces the CEDB to evaluate low-carbon design strategies for dairy barns, integrating building layout, ventilation systems, and energy sources in a unified assessment approach, providing valuable insights for the low-carbon transition of agricultural buildings.

Governments across the world are taking actions to address the high carbon emissions associated with the construction industry, and to achieve the long-term goals of the Paris Agreement towards carbon neutrality. Although the ideal of the carbon-emission reduction in building projects is well acknowledged and generally accepted, it is proving more difficult to implement. The application of building information modeling (BIM) brings about new possibilities for reductions in carbon emissions within the context of sustainable buildings. At present, the studies on BIM associated with carbon emissions have concentrated on the design stage, with the topics focusing on resource efficiency (namely, building energy and carbon-emission calculators). However, the effect of BIM in reducing carbon emissions across the lifecycle phases of buildings is not well researched. Therefore, this paper aims to examine the relationship between BIM, carbon emissions, and sustainable buildings by reviewing and assessing the current state of the research hotspots, trends, and gaps in the field of BIM and carbon emissions, providing a reference for understanding the current body of knowledge, and helping to stimulate future research. This paper adopts the macroquantitative and microqualitative research methods of bibliometric analysis. The results show that, in green-building construction, building lifecycle assessments, sustainable materials, the building energy efficiency and design, and environmental-protection strategies are the five most popular research directions of BIM in the field of carbon emissions in sustainable buildings. Interestingly, China has shown a good practice of using BIM for carbon-emission reduction. Furthermore, the findings suggest that the current research in the field is focused on the design and construction stages, which indicates that the operational and demolition stages have greater potential for future research. The results also indicate the need for policy and technological drivers for the rapid development of BIM-driven carbon-emission reduction.