Comparative Study on Life-Cycle Assessment and Carbon Footprint of Hybrid, Concrete and Timber Apartment Buildings in Finland

To date, in the literature, there has been no study on the comparison of hybrid (timber and concrete) buildings with counterparts made of timber and concrete as the most common construction materials, in terms of the life cycle assessment (LCA) and the carbon footprint. This paper examines the environmental impacts of a five-story hybrid apartment building compared to timber and reinforced concrete counterparts in whole-building life-cycle assessment using the software tool, One Click LCA, for the estimation of environmental impacts from building materials of assemblies, construction, and building end-of-life treatment of 50 years in Finland. Following EN 15978, stages of product and construction (A1–A5), use (B1–B6), end-of-life (C1–C4), and beyond the building life cycle (D) were assessed. The main findings highlighted are as following: (1) for A1–A3, the timber apartment had the smallest carbon footprint (28% less than the hybrid apartment); (2) in A4, the timber apartment had a much smaller carbon footprint (55% less than the hybrid apartment), and the hybrid apartment had a smaller carbon footprint (19%) than the concrete apartment; (3) for B1–B5, the carbon footprint of the timber apartment was larger (>20%); (4) in C1–C4, the carbon footprint of the concrete apartment had the lowest emissions (35,061 kg CO2-e), and the timber apartment had the highest (44,627 kg CO2-e), but in D, timber became the most advantageous material; (5) the share of life-cycle emissions from building services was very significant. Considering the environmental performance of hybrid construction as well as its other advantages over timber, wood-based hybrid solutions can lead to more rational use of wood, encouraging the development of more efficient buildings. In the long run, this will result in a higher proportion of wood in buildings, which will be beneficial for living conditions, the environment, and the society in general.

IFC TO CITYGML CONVERSION ALGORITHM BASED ON GEOMETRY AND SEMANTIC MAPPING

Geographic information system (GIS) is known traditionally for the modelling of two-dimensional (2D) geospatial analysis and therefore present information about the extensive spatial framework. On the other hand, building information modelling (BIM) is digital representation of building life cycle. The increasing use of both BIM and GIS simultaneously because of their mutual relationship, as well as their similarities, has resulted in more relationships between both worlds, therefore the need for their integration. A significant purpose of these similarities is importing BIM data into GIS to significantly assist in different design-related issues. However, currently this is challenging due to the diversity between the two worlds which includes diversity in coordinate systems, three-dimensional (3D) geometry representation, and semantic mismatch. This paper describes an algorithm for the conversion of IFC data to CityGML in order to achieve the set goal of sharing information between BIM and GIS domains. The implementation of the programme developed using python was validated using an IFC model (block HO2) of a student’s hostel, Kolej Tun Fatima (KTF). The conversion is based on geometric and semantic information mapping and the use of 3D affine transformation of IFC data from local coordinate system (LCS) to CityGML world coordinate system (WCS) (EPSG:4236). In order to bridge the gap between the two data exchange formats of BIM and GIS, we conducted geometry and semantic mapping. In this paper, we limited the conversion of the IFC model on level of details 2 (LOD2). The conversion will serve as a bridge toward the development of a software that will perform the conversion to create a strong synergy between the two domains for purpose of sharing information.

Mass Timber Building Life Cycle Assessment Methodology for the U.S. Regional Case Studies

The building industry currently consumes over a third of energy produced and emits 39% of greenhouse gases globally produced by human activities. The manufacturing of building materials and the construction of buildings make up 11% of those emissions within the sector. Whole-building life-cycle assessment is a holistic and scientific tool to assess multiple environmental impacts with internationally accepted inventory databases. A comparison of the building life-cycle assessment results would help to select materials and designs to reduce total environmental impacts at the early planning stage for architects and developers, and to revise the building code to improve environmental performance. The Nature Conservancy convened a group of researchers and policymakers from governments and non-profit organizations with expertise across wood product life-cycle assessment, forest carbon, and forest products market analysis to address emissions and energy consumption associated with mass timber building solutions. The study disclosed a series of detailed, comparative life-cycle assessments of pairs of buildings using both mass timber and conventional materials. The methodologies used in this study are clearly laid out in this paper for transparency and accountability. A plethora of data exists on the favorable environmental performance of wood as a building material and energy source, and many opportunities appear for research to improve on current practices.

APPLICATION OF BIM-TECHNOLOGIES IN THE DEVELOPMENT OF ARCHETECTURAL, STRUCTURAL AND ORGANIZATIONAL-TECHNOLOGICAL SULUTIINS OF AN INDUSTRIAL BUILDING

Recently, more and more attention has been paid to the potential benefits of BIM in construction. Effective communication between stakeholders at all stages of the building life cycle has become a major challenge in the global industry. The implementation of Building Information Modeling (BIM) has been recognized as a productive approach to solving this problem. A literature review identified key issues related to the use and implementation of BIM. This article presents the design of an industrial building (architectural, structural, organizational and technical solutions) using four software systems, shows the practical experience of optimizing the construction of a workshop based on the data of the information model of the building.

BIM Technology Application Strategy in the Whole Life Cycle of Green Building

This paper summarizes the concept, influencing factors, principles and design methods of green building by combing the relevant research of green building at home and abroad. On this basis, this paper takes the whole life cycle practice process as the main line, and puts forward the specific application strategy of corresponding BIM Technology for the bottleneck problem of traditional technology in each stage. Then this paper demonstrates the unique advantages and feasibility of BIM Technology through practical cases. Among them, BIM Technology integrates geometric model and attribute database, and realizes the organic combination of spatial data and attribute data. The test results show that the BIM calculation and analysis function and ecological condition simulation function provide a very effective performance analysis tool and auxiliary decision-making tool for green building project participants. This paper studies the relationship between green building, life cycle and BIM, and puts forward constructive BIM application strategies, hoping to provide scientific reference for green building practice and related research, so as to achieve the goal of healthy and sustainable development of construction industry.

The Influence of Construction Materials on Life-Cycle Energy Use and Carbon Dioxide Emissions of Medium Size Commercial Buildings

<p>This thesis studies the influence of construction materials on the life-cycle energy consumption and carbon dioxide (CO2) emissions of medium sized low energy consumption commercial buildings. When describing buildings by materials, there is a tendency to label them according to the main structural material used. However, the vast majority of commercial buildings use a large number of materials. Hence it is not clear which materials or combinations of materials can achieve the best performance, in terms of lifecycle energy use and CO2 emissions. The buildings analysed here were based on an actual six-storey 4250m2 (gross floor area) building, with a mixed-mode ventilation system, currently under construction at the University of Canterbury in Christchurch. While the actual building is being constructed in concrete, the author has designed two further versions in which the structures and finishes are predominantly steel or timber. Despite having different structural materials, large quantities of finishes materials are common to all three buildings; large glazed curtain walls and sun louvers, stairs balustrade and most of the offices internal finishes. A fourth building was also produced in which all possible common finishes' of the timber building were replaced by timber components. This building is labelled as Timber-plus and was included to assess the difference of the three initial 'common finishes' buildings against a building that might be expected to have a low or even negative total embodied CO2 emission in structure and finishes. In order to highlight the influence of materials, each building was designed to have a similar indoor climate with roughly the same amount of operational energy for heating and cooling over its full life. Both energy use and CO2 emissions have been assessed over three main stages in the life (and potential environmental impact) of a building: initial production of the building materials (initial embodied energy and initial embodied CO2 emissions); operation of the building (mainly in terms of its energy use); and the refurbishment and maintenance of the building materials over the building's effective life (recurrent embodied energy and CO2 emissions). Calculation of embodied energy and embodied CO2 emissions are based on materials' estimates undertaken by a Quantity Surveyor. DesignBuilder software was used to estimate whole life-cycle energy used and CO2 emitted in the operation of the buildings over a period of 60 years. Two different methods for embodied energy and embodied CO2 calculation were applied to the four buildings. The first method was by multiplying the volume of each material in the schedule calculated by the Quantity Surveyor by the New Zealand specific coefficients of embodied energy and embodied CO2 produced by Andrew Alcorn (2003). The second method was analysing the same schedule of materials with GaBi professional LCA software. Materials' inventories in GaBi are average German industry data collected by PE Europe between 1996 and 2004 (Alcorn, 2003; Nebel & Love, 2008). The energy results of the thesis show that when using the Alcorn coefficients, the total embodied energy (initial plus recurrent embodied energy) averaged 23% and operating energy consumption averaged 77% of the total life-cycle energy consumption for the four buildings. Using the GaBi coefficients, total embodied energy averaged 19% and operating energy consumption averaged 81% of the total life-cycle energy consumption of the four buildings. Using the Alcorn coefficients, the difference between the highest (steel building) and lowest (timber-plus building) life-cycle energy consumption represents a 22% increment of the highest over the lowest. Using the GaBi coefficients, the difference between the lowest (timber-plus building) and the highest (timber building) life-cycle energy consumption represents a 15% increment of the highest over the lowest. The CO2 results shows that when using the Alcorn coefficients, the total embodied CO2 emissions averaged 7% and operating CO2 emissions averaged 93%. Using the GaBi coefficients, total embodied CO2 emissions averaged 16% and operating CO2 emissions averaged 84% of the life-cycle CO2 emissions of the four buildings. Using the Alcorn coefficients, the difference between the highest (steel building) and lowest (timber-plus building) life-cycle CO2 emissions represents a 27% increment of the highest over the lower. Using the GaBi coefficients, the difference between the highest (timber building) and the lowest (timber-plus building) lifecycle CO2 emissions represents a 9% increment of the highest over the lowest. While for the case of embodied energy the Alcorn results averaged 32% higher than the GaBi, in the case of embodied CO2 the Alcorn results averaged 62% lower than the GaBi. Major differences in the results produced when using the two different sets of embodied energy and CO2 coefficients are due mainly to their different approaches to the CO2 sequestration in timber materials. While the Alcorn coefficients account for the CO2 sequestration of timber materials, the GaBi coefficients do not. This is particularly noteworthy as the CO2 sequestration of timber has been neglected in previous research. It was established that embodied energy can significantly influence the life-cycle energy consumption and CO2 emissions of contemporary low energy buildings. Using the Alcorn coefficients, the steel building embodied the equivalent of 27 years of operating energy consumption and 12 years of operating CO2 emissions. At the other end of the spectrum the timber-plus building embodied the equivalent of 11 years of operating energy consumption and has stored the equivalent of 3.6 years of operating CO2 emissions. Using the GaBi coefficients, the steel building embodied the equivalent of 19 years of operating energy consumption and 14 years of operating CO2 emissions, while the timber-plus building embodied the equivalent of 8 years of operating energy consumption and 8 years of operating CO2 emissions. These findings are of significance, for example, in the assessment and weighting of the embodied energy and embodied CO2 components of building sustainable rating tools.</p>

The Influence of Construction Materials on Life-Cycle Energy Use and Carbon Dioxide Emissions of Medium Size Commercial Buildings

<p>This thesis studies the influence of construction materials on the life-cycle energy consumption and carbon dioxide (CO2) emissions of medium sized low energy consumption commercial buildings. When describing buildings by materials, there is a tendency to label them according to the main structural material used. However, the vast majority of commercial buildings use a large number of materials. Hence it is not clear which materials or combinations of materials can achieve the best performance, in terms of lifecycle energy use and CO2 emissions. The buildings analysed here were based on an actual six-storey 4250m2 (gross floor area) building, with a mixed-mode ventilation system, currently under construction at the University of Canterbury in Christchurch. While the actual building is being constructed in concrete, the author has designed two further versions in which the structures and finishes are predominantly steel or timber. Despite having different structural materials, large quantities of finishes materials are common to all three buildings; large glazed curtain walls and sun louvers, stairs balustrade and most of the offices internal finishes. A fourth building was also produced in which all possible common finishes' of the timber building were replaced by timber components. This building is labelled as Timber-plus and was included to assess the difference of the three initial 'common finishes' buildings against a building that might be expected to have a low or even negative total embodied CO2 emission in structure and finishes. In order to highlight the influence of materials, each building was designed to have a similar indoor climate with roughly the same amount of operational energy for heating and cooling over its full life. Both energy use and CO2 emissions have been assessed over three main stages in the life (and potential environmental impact) of a building: initial production of the building materials (initial embodied energy and initial embodied CO2 emissions); operation of the building (mainly in terms of its energy use); and the refurbishment and maintenance of the building materials over the building's effective life (recurrent embodied energy and CO2 emissions). Calculation of embodied energy and embodied CO2 emissions are based on materials' estimates undertaken by a Quantity Surveyor. DesignBuilder software was used to estimate whole life-cycle energy used and CO2 emitted in the operation of the buildings over a period of 60 years. Two different methods for embodied energy and embodied CO2 calculation were applied to the four buildings. The first method was by multiplying the volume of each material in the schedule calculated by the Quantity Surveyor by the New Zealand specific coefficients of embodied energy and embodied CO2 produced by Andrew Alcorn (2003). The second method was analysing the same schedule of materials with GaBi professional LCA software. Materials' inventories in GaBi are average German industry data collected by PE Europe between 1996 and 2004 (Alcorn, 2003; Nebel & Love, 2008). The energy results of the thesis show that when using the Alcorn coefficients, the total embodied energy (initial plus recurrent embodied energy) averaged 23% and operating energy consumption averaged 77% of the total life-cycle energy consumption for the four buildings. Using the GaBi coefficients, total embodied energy averaged 19% and operating energy consumption averaged 81% of the total life-cycle energy consumption of the four buildings. Using the Alcorn coefficients, the difference between the highest (steel building) and lowest (timber-plus building) life-cycle energy consumption represents a 22% increment of the highest over the lowest. Using the GaBi coefficients, the difference between the lowest (timber-plus building) and the highest (timber building) life-cycle energy consumption represents a 15% increment of the highest over the lowest. The CO2 results shows that when using the Alcorn coefficients, the total embodied CO2 emissions averaged 7% and operating CO2 emissions averaged 93%. Using the GaBi coefficients, total embodied CO2 emissions averaged 16% and operating CO2 emissions averaged 84% of the life-cycle CO2 emissions of the four buildings. Using the Alcorn coefficients, the difference between the highest (steel building) and lowest (timber-plus building) life-cycle CO2 emissions represents a 27% increment of the highest over the lower. Using the GaBi coefficients, the difference between the highest (timber building) and the lowest (timber-plus building) lifecycle CO2 emissions represents a 9% increment of the highest over the lowest. While for the case of embodied energy the Alcorn results averaged 32% higher than the GaBi, in the case of embodied CO2 the Alcorn results averaged 62% lower than the GaBi. Major differences in the results produced when using the two different sets of embodied energy and CO2 coefficients are due mainly to their different approaches to the CO2 sequestration in timber materials. While the Alcorn coefficients account for the CO2 sequestration of timber materials, the GaBi coefficients do not. This is particularly noteworthy as the CO2 sequestration of timber has been neglected in previous research. It was established that embodied energy can significantly influence the life-cycle energy consumption and CO2 emissions of contemporary low energy buildings. Using the Alcorn coefficients, the steel building embodied the equivalent of 27 years of operating energy consumption and 12 years of operating CO2 emissions. At the other end of the spectrum the timber-plus building embodied the equivalent of 11 years of operating energy consumption and has stored the equivalent of 3.6 years of operating CO2 emissions. Using the GaBi coefficients, the steel building embodied the equivalent of 19 years of operating energy consumption and 14 years of operating CO2 emissions, while the timber-plus building embodied the equivalent of 8 years of operating energy consumption and 8 years of operating CO2 emissions. These findings are of significance, for example, in the assessment and weighting of the embodied energy and embodied CO2 components of building sustainable rating tools.</p>