This project performed to develop the NRC OpenBIM web application to facilitate Building Information Modelling (BIM)-based model validation for smart decarbonization of the built environment through Life Cycle Assessment (LCA) modelling, auto mapping the bill-of-work data with life cycle inventory datasets at different life cycle stages and generate a robust LCA results for benchmarking purposes.
Reviewing the recent studies on decarbonization policies in the built environment, tools and technics along with the recent progresses on BIM and decarbonization, limited practices are witnessed related to implementing innovative technologies into decarbonization policies issued by public services. One challenge lies in the lack of methodological details to define the framework of BIM and decarbonization systematically with a view to promote decision-making in the construction sector and to protect the built environment. This BIM integrated approach specifically the concept of OpenBIM, which is universal approach to the collaborative design, realization and operation of the built environment based on open standards and workflows, is considered as a key contribution to aid standardization of whole-building LCA practice and to add records to the bill-of-work database, which will host records for potentially hundreds or thousands of buildings. This approach will use industry foundation classes (IFC) to transfer the data exported from BIM models to life cycle environmental assessment tool. It is commonly known that IFC scheme for storing carbon related information within BIM environment is a workable method to cope with a big volume of data. The whole web application development is in direct alignment with standardization of data exchange format and digital platform to be referenced and used by practitioners. The outcomes of this project are enhancing the construction sector productivity through optimizing the GHG emission from early design stages in building projects (Figure 1).
The Canadian construction sector faces many challenges when it comes to modernization and decarbonization. In order to improve business outcomes and productivity, the construction sector must, across all its segments, adopt digitalization. To accelerate this national paradigm-shift, at-scale, a multi-faceted approach is required. The smart decarbonization solutions through using BIM/ digital twin will have a ripple effect through the complex construction value chain. Research and Development on digital construction is only just emerging in Canada, leaving many gaps and no significant inroads to domestic implementation at scale. Despite several recent works which performed BIM-related integration, one challenge in the incorporation of BIM and decarbonization lies in the lack of methodological details to define the framework of BIM and environmental impacts assessment systematically with a view to promote decision-making in the construction sector and to protect the built environment. Reviewing the recent studies on decarbonization policies in built environment, tools and technics along with the recent progresses on BIM and LCA integration area, limited practices are witnessed related to implementing innovative technologies into low carbon policies issued by public services. The review outcomes show that BIM-related decarbonization studies mostly focused on manual and semi-automatic solutions at the early design stages. It is also specified that all design variations still have not been addressed in order to enhance the results validation to complete the automation of the environmental impacts assessment process. A comprehensive approach must fully address GHG emissions benchmarking or the one that considers the whole life cycle and includes embodied carbon, operational carbon, and carbon released at the end of the service life of the buildings and infrastructures.
Early adopters at the Government of Canada can initiate pilot projects and demonstrations where the NRC OpenBIM web application tool is used to design and construct environmentally friendly buildings or infrastructure. These projects can serve as showcases of sustainable practices, encouraging private developers and industries to follow suit. The use of standard naming convention as well as the approved master specification in the NRC OpenBIM web application tool can encourage the private sector to use the tool voluntarily and recognizing and incentivizing sustainable design and construction through regulatory frameworks will boost its adoption. Manufacturers and suppliers of building materials and systems can use the implemented web app to assess and demonstrate the environmental impact of their products, which can influence the choices made by architects and contractors. NRC OpenBIM web application tool will support architects and designers in making environmentally conscious decisions during the early design stages. They can assess the environmental impact of different design alternatives, such as building assembly choices, building orientation, and energy efficiency measures. Construction professionals can use such tools to optimize construction processes, minimize waste, and select low-carbon materials, leading to reduced greenhouse gas emissions during the construction phase. Municipalities interested in sustainability and green building practices use the NRC OpenBIM web application tool to assess and certify buildings’ environmental performance, such as obtaining Leadership in Energy and Environmental Design (LEED) or other green building certifications.
Integration of BIM and decarbonization solutions is the efficient way to obtain necessary information about the construction materials used in BIM models and transferring them to the existing carbon inventory database outcomes. It is obvious that there is considerable difference between the formats of the data recognized by both the LCA and BIM tools. To map the data extracted from a BIM model, a consistent data format and similar naming convention must be established when a link between BIM and LCA is to be set. During the data transition, information from BIM models is transferred into environmental impacts assessment tools to determine the results. There are different methods identified from past research to bilaterally transfer information and data between BIM models and LCA tool. Using openBIM and the Industry Foundation Classes (IFC) as a data exchange format is often considered a favorable method to integrate BIM and LCA for several reasons such as interoperability functionalities, rich data representation, consideration of the whole life cycle perspectives, data consistency along with standardized information, and finally the automation and efficiency in calculation of environmental impacts of construction materials and components and ultimately the whole-asset scale. The output of this project will lead to establish the NRC OpenBIM web application and performance level benchmarks guideline, methodology and proof of concept for the bill of works for Canadian building archetypes to be in line with the NRC guidelines.
A 2-story clinic office building with a total gross area of 1005.35 m2 and 781.91 m2 net conditioned area was studied as a case example project. The BIM design is prepared based on the level of details (LOD 350) in order to meet the minimum criteria for environmental impacts assessment including the materials keynotes, assembly codes and products labeling and the extracted IFC file has been used to be tested in the NRC web application as a proof-of-concept model (Figure 2).
Development of an open-source model checker engine in order to validate any IFC files exported from BIM models to assess the minimum requirements of the model against decarbonization studies (e.g. level of details, masterspecification assignments for materials and components, etc.) with capability of proposing alternative solutions for missing data to prepare the robust and enhanced IFC file ready for life cycle environmental impacts assessment practices. This task requires reviewing methods focusing on materials annotation and specification functions (i.e. uniformat, masterformat) as well as data mapping between bill of materials database to provide a highly compliant BIM- integrated framework through using a comprehensive environmental inventory database of generic and specific data. The most recent version of IFC, which is the IFC4, is the only version that makes use of IFC features for simple environmental assessment. Therefore, one important outcome of this project is to develop an IFC reader engine with the capability of incorporating more IFC properties for a whole building environmental impacts benchmarking purpose. Development of such application enables integration of the design specifications with a real time building materials and component quantity take-offs extraction along with energy and environmental performance analysis results from early design stages of building’s life cycle, which is a crucial step to move the benchmarking framework into implementation to harmonize data collection and processing practices (Figure 3).
In this web application, through selecting the office building lifespan to be 60 years as well accounting for regional specifications, key building attributes were specified. The production stage includes the data mapping between the materials quantity take-offs extracted from the BIM model with the inventory list where the database was used in the backend of the application. Therefore, the user can track and manage data mapping to ensure all the materials used in the project have been modeled and considered in the impacts assessment. By selecting each item, the list of all relevant gate-to-gate processes in datasets for materials production, transportation and manufacturing are shown and the user selects the most appropriate products/activities. For products that the environmental products declaration (EPD) documents are available, there is a functionality in this application to import the kgCO2eq per unit function of the product to be considered for that specific product (e.g. facility specific ready-mixed concrete EPDs). The environmental datasets are pre-filtered in the application which enables a short list of appropriate materials/activities/ processes for the user to select from. The application takes the quantify take off from the BIM model and indicates the mapped items with color coding.
For the construction phase the application offers three tabs where first all the materials used and associated transportation requirements across each building element were specified. The distance between manufacturing (or regional storage) and construction site can be automatically calculated by area code (e.g. postal code) via a google map feature. The building construction process includes the quantification of installation and excavation energy and the amount of building material waste generated on site. The next tab is related to the machines and equipment used in the construction projects (e.g. hydraulic loader or crane). Since construction equipment are used on an hourly basis, they are assigned to the whole building process. The construction design and excavation activities require both fossil fuels and electricity. Wasted material generation were considered based on common waste factors of the structural materials (i.e. concrete, steel, gypsum etc.) which are assumed to be transported to a waste sorting facility with an assumed distance of 100 km.
Embodied impacts also occur during the use phase of the building due to replacement and maintenance of building elements during the whole building life cycle. Material replacement is included in the maintenance phase on the basis of each material’s service life. The list of elements that are extracted from the BIM model are displayed in the web app and the user can define element-wise life expectancies. For the office building, painting was assumed to be performed every 5 years and doors, windows and curtain walls were assumed to be replaced every 20 years while the insulation and structural components were assumed to remain for the entire life cycle of the building.
The end-of-life stage includes an activity section similar to the construction stage. The electricity at the demolition stage is the fossil fuel needed to power the deconstruction machines in the building. The end user can also select whether each building element should be disposed of or recycled and thus link to an appropriate dataset activity. The material disposal stage is modeled based on the building assembly classification. The demolished material was assumed to be transported from the building site to a landfill or waste sorting facility, and in this study, a distance of 100 km was assumed. The sample results of the environmental impacts with the detailed results of contribution analysis are shown in Figure 4.
From a quantitative perspective, through using integration approaches for material selection and construction optimization, projects can significantly reduce the embodied carbon in buildings. This reduction can vary depending on the materials chosen, but it can potentially result in several percentage points of GHG emissions reduction during the construction phase. This practice can also lead to better energy-efficient designs and retrofit solutions. Improved energy performance can lead to reduced operational carbon emissions over the life cycle of the building, potentially resulting in substantial GHG reductions over time. Automating construction processes within BIM can reduce material waste and related emissions as well. Instances from quantitative studies have shown potential improvements in carbon reduction through integration which led to reductions in embodied carbon of 20-30% compared to traditional design methods. This approach helped identify potential carbon emissions reductions of up to 50% during the construction and operational phases of a building’s life cycle as well. From qualitative approach, it enables better-informed decision-making by providing stakeholders with comprehensive environmental data. This can lead to more sustainable choices, which contribute to a positive impact on GHG emissions. The widespread adoption of integrated practices can drive the construction and building industry towards a more sustainable path. It encourages innovation in low-carbon technologies and practices, leading to broader systemic changes in the industry over time. These practices can support the development of environmental policies and regulations by providing data and insights on the environmental impacts of buildings.
This project is a transformative solution poised to positively impact the construction industry in several key ways. It offers a comprehensive approach to assessing and mitigating the environmental impact of building projects, emphasizing the importance of sustainability throughout a building’s entire life cycle. One of its primary contributions is the establishment of standardized benchmarks for environmental performance. By creating a framework that aligns with industry standards and regulations, the project provides a credible baseline against which building projects can be compared. This benchmarking system is crucial for setting performance targets, measuring the effectiveness of sustainability policies, and encouraging the adoption of best practices in green building programs. OpenBIM standards enhance data interoperability, enabling seamless data exchange across different project stages. This, in turn, enhances efficiency in decision-making and procurement processes, ultimately reducing the environmental impact of construction projects. The project also champions digitalization and automation, simplifying data collection and analysis while promoting collaboration among stakeholders throughout the supply chain.
This project promotes enhanced sustainability and encourages data-driven decision-making that can significantly reduce the environmental footprint of buildings. This shift towards sustainability is critical for combating climate change and preserving our planet for future generations. Reducing the environmental impact of construction leads to cleaner ecosystems, benefiting not only the environment but also the well-being of people. On a global scale, Canada’s leadership in sustainable construction technology can contribute to worldwide efforts to address climate change and promote sustainable urban development. By sharing expertise and technology, Canada can have a significant impact on a global scale. This project also fosters ongoing innovation and research in the construction sector, potentially leading to breakthroughs in materials science, construction techniques, and renewable energy integration. This project’s influence on policies and regulations related to green building practices can encourage governments to incentivize sustainability and set stricter environmental standards. These changes can have a cascading effect on industry and society as a whole. Collectively, these benefits can lead to a more sustainable, prosperous, and healthier civilization, making it a valuable contribution to our global community.
