3.1. BIM 3D Modeling Software
BIM 3D modeling software enables advanced digital modeling and information management, making it a key technological component of the BIM process [
8]. This software has the potential to streamline environmental performance assessments of buildings by reducing the additional workload required for life cycle assessment (LCA) and accelerating the process [
9]. BIM software creates virtual models that include graphical information, construction materials, and component data.
Table 1 highlights three commonly used BIM software platforms—Autodesk Revit, The Beck Group DProfiler, and Graphisoft ArchiCAD—while outlining their features and limitations in the context of LCA applications.
One of the most widely used BIM programs is Autodesk Revit, which manages and stores data related to building structures [
10], earning a reputation as the best BIM software [
11]. Revit offers tools for designing building elements, public utilities, and structural engineering, particularly excelling in projects with complex geometry and high computational demands across a variety of applications. It is efficient in importing, exporting, and linking data in standard formats, allowing for rapid 3D visualization and offering better insights into a project before implementation [
12]. The detailed modeling capability allows for accurate recording of structural elements like rebar. Revit also reduces repetition during model creation and measures how different components interact with their environment.
However, Revit does have its challenges. The lack of built-in design tools makes it more difficult to design projects as accurately as with specialized software. Calculating energy consumption and CO2 emissions with Revit and Excel can be time-consuming, especially due to mismatches between Revit’s material database and the ecoinvent LCI database, where differing units present a further challenge. Interoperability issues also persist, and the types of information and reports Revit generates are often insufficient for certain tasks [
13]. Additionally, files like portable document format (.pdf) and extensible markup language (.xml) from Revit are limited, as programs like Excel cannot properly interpret the data. Moreover, Lu, Jiang [
14] noted that Autodesk Revit loses components and information when transferring data to Glondon GTJ2018, raising concerns about potential data loss when exporting Revit data into LCA models. Revit’s integration with Athena is limited, as it only supports modeling for individual components such as walls and doors, rather than entire buildings.
Another modeling software, DProfiler, was developed to automatically export BIM data into energy modeling applications [
15,
16,
17]. DProfiler provides detailed feedback on material quantities and energy analysis with minimal architectural design input, producing detailed BIM data from much smaller input values compared to alternatives like Revit [
18]. It simplifies the process of acquiring conceptual design models and generating precise cost estimates, allowing for value analysis of different design options based on construction specifications and associated costs. However, DProfiler is limited in that it does not support complex or free-form building shapes, handling only simple orthogonal structures. Its primary use is in the economic evaluation of construction projects, and its interface is not as well-suited for integration with other BIM software. As a result, DProfiler is less commonly used in European markets [
19]. Additionally, missing architectural elements and incomplete information on geometric parts in the BIM model can lead to an incomplete bill of quantities, which in turn impacts the completeness of LCA results.
Another widely used BIM design software is ArchiCAD, developed by the American company Graphisoft and certified by buildingSMART’s Industry Foundation Classes (IFC). ArchiCAD allows users to perform budget calculations by inputting the unit costs of materials and resources, extract all quantitative data, and export it into Excel. It also enables users to input precise carbon footprint values for each material in kgCO2 per kilogram. However, unlike SimPro, which measures carbon emissions in kgCO2 per square meter, ArchiCAD calculates emissions in kgCO2 per kilogram, making it impossible to automatically transfer carbon footprint data to LCA software [
20].
Despite this, ArchiCAD files show strong convergence of measured values, and its compatibility with environmental settings and climate data allows precise positioning of reference buildings, making environmental simulations more efficient [
21]. On the downside, ArchiCAD involves a complex process of removing doors already present in the model, a step not required in Revit, which simplifies the validation process. Additionally, ArchiCAD's compressed IFC files take longer to load, which can negatively impact productivity and file conversion efficiency. This can be improved by using optimized compression tools like IFCCompressor to remove redundant data from the files, speeding up the model loading process [
22].
However, ArchiCAD has some limitations in custom parametric modeling due to its reliance on the parametric programming language GDL, which demands a higher level of programming expertise compared to Revit's more user-friendly visualization of family components. Furthermore, ArchiCAD depends on a separate plug-in, MEPModeler, for mechanical, electrical, and plumbing (MEP) modeling. This plug-in lacks the capability to calculate ventilation and electrical loads, which diminishes the quality of the LCA results.
3.2. LCA Tools
Life Cycle Assessment (LCA) is a methodology developed to evaluate the environmental impacts of a product throughout its entire life cycle. This includes all stages from raw material extraction, manufacturing, transportation, construction, operation, maintenance, to end-of-life processing and recycling [
28]. According to ISO standards 14040-14044, LCA involves the collection and evaluation of the inputs, outputs, and potential environmental impacts associated with a system over its full life cycle [
2]. The LCA process is inherently complex and time-consuming, further complicated by issues such as software interoperability, calculation methods, and database compatibility.
Table 2 outlines the characteristics and limitations of LCA tools that are applicable in conjunction with BIM software.
One of the most widely used LCA tools is SimaPro, which was designed for integrated waste management, life cycle analysis, carbon and water footprinting, product design, and the development of environmental product claims. It also supports the identification of key performance indicators and sustainability reporting [
45]. SimaPro significantly reduces the time required for conducting a life cycle analysis. Compared to GaBi, SimaPro offers greater flexibility and ease of use, with unrestricted editing capabilities and access to Life Cycle Inventory (LCI) databases [
46,
47]. However, SimaPro does have limitations, such as its inability to model a variety of suppliers within the LCI dataset, and the need for further development of connectivity between different product modules.
Another challenge with SimaPro is that, due to differences in BIM plug-in tools, the results from LCA calculations conducted in SimaPro cannot be directly correlated with the energy and carbon assessment results from BIM tools. This lack of seamless integration between LCA and BIM energy modeling remains a key area for improvement in future development.
The openLCA tool offers a user-friendly interface and supports original databases, allowing users to construct graphical models either manually or automatically. However, the validity of LCA results often depends on the referenced database, as openLCA is a free, open-source platform. Users must manually input data into the system, which limits convenience [
48,
49]. Additionally, its time-consuming calculations make openLCA slower compared to other tools like SimaPro. Moreover, specialized LCA tools such as openLCA and SimaPro do not evaluate material usage in the building process, reducing the reliability of their LCA assessments. Manually generated modules also lower the efficiency of interacting with BIM data and increase the risk of errors.
Tally, a Revit plug-in, facilitates the exchange of alphanumeric and graphical data. It extracts building materials inventory data and evaluates environmental impact categories in accordance with the U.S. EPA’s TRACI framework, covering all stages of the material life cycle, from extraction and manufacturing to end-of-life [
50]. Tally is useful for assessing the environmental effects of various building materials, making it suitable for comparative design studies and comprehensive building analyses. Furthermore, Tally can be integrated with the GaBi database, enabling the extraction of material data from the BIM model—an advantage over Athena software [
51]. However, Tally has limitations, such as the inability to model LCA data directly for items outside of the database, which reduces the reliability of LCA reports [
52]. Additionally, both Tally and Athena struggle to recognize materials chosen for Revit projects. Their databases are rigid and limited, making it difficult to edit material information and affecting the accuracy of LCA analyses. With fewer material options, Tally often requires assumptions about which building components might be used.
Umberto NXT offers efficient tools for creating flowcharts and Sankey diagrams, which help users visualize environmental impacts quickly. This software allows graphical modeling and analysis across several midpoint and endpoint categories, helping to assess and visualize the environmental effects of products [
53,
54]. It features an intuitive interface, automated calculations, and integrated functions that boost operational efficiency. Despite its strong performance and ease of use, Umberto NXT lacks additional advanced features [
36]. One limitation is that it is not web-based, and applying it within BIM workflows requires experienced LCA specialists. This need for expert knowledge poses challenges for professionals in the architecture, engineering, and construction (AEC) industry, as additional work is required to streamline its integration.
The Athena Impact Estimator and Athena EcoCalculator are free LCA tools developed by the Athena Institute, with the primary function of calculating a building’s carbon footprint and providing environmental impact data in spreadsheet format [
55]. The EcoCalculator requires minimal input and provides environmental effect calculations based on these inputs, though it lacks flexibility in terms of modifying LCI data sources or conducting sensitivity analyses. The Athena Impact Estimator has an advantage over the EcoCalculator in terms of BIM interoperability, allowing users to import bills of materials from CAD programs [
37]. However, both tools can suffer from missing elements and potentially erroneous results [
41].
Despite the Athena tools' capabilities, there are limitations, particularly in the availability of LCI cell processes, which users cannot modify. In contrast, SimaPro allows users to manually select LCI unit processes, offering more control and precision [
46]. The variance in LCA results is also dependent on the software being used, as each tool utilizes different databases and implementation scopes, leading to differences in calculating environmental impact factors. For example, a study on Brazilian particleboard by Lopes Silva, Nunes [
56] demonstrated discrepancies in environmental impact findings when using SimaPro, Gabi, Umberto, and openLCA. These differences were attributed to variations in the background databases and the import process, which could be restricted or fail altogether. Additionally, the versions of standards used by each software tool contributed to variations in environmental effect outcomes [
57].
Research by Al-Ghamdi and Bilec [
46] revealed a 10% difference in global warming potential when comparing results from the Athena Impact Estimator, Tally, and SimaPro, highlighting the impact of software selection on LCA outcomes. These variations emphasize the importance of choosing the right LCA tool based on project needs and the scope of environmental impact assessment.
3.3. Energy Consumption Tool Compatibility
Building energy modeling is crucial for setting baselines and managing building energy, particularly in relation to LCA. Energy consumption tools must be compatible with BIM models to ensure accurate predictions and support environmental impact analysis [
58]. The interoperability between energy consumption tools and BIM is critical for efficiency and accuracy in data exchange, as seen in the common tools listed in Table 3.
Designbuilder is a well-known tool that integrates with the EnergyPlus dynamic thermal simulation engine, providing graphical models and environmental performance data. Designbuilder imports BIM models via the gbXML format, which is highly efficient for transferring geometric data between BIM software and energy simulation tools. The process saves time by eliminating the need to manually generate building geometry within the simulation interface [
70]. However, users must manually modify the software’s default values to reflect the specific project, as relying on defaults can lead to inaccurate results [
61].
Green Building Studio (GBS) is a web-based energy analysis tool that is free to use and provides fast graphical feedback. One of GBS's key advantages is its ability to perform additional scenario simulations alongside regular energy calculations, which enhances its utility for more complex energy analysis projects [
64]. It is also highly user-friendly, allowing users with minimal programming or energy analysis expertise to engage with the tool effectively. However, like Designbuilder, GBS's reliance on automated default settings can introduce errors in the simulations if these values are not carefully adjusted to fit project-specific requirements [
63].
3.3.1. Integrated Environmental Simulation Tools
Integrated Environmental Solutions®—Virtual Environment (IES-VE) is a comprehensive platform that integrates several applications into a single data model for building simulations, covering areas like energy, daylighting, renewable systems, and airflow performance [
72]. One of the key strengths of IES-VE is its two-way data exchange, which simplifies geometric data parameter inputs from BIM models. However, despite its robustness, it is not widely popular due to its high cost [
65].
Autodesk Ecotect accepts output from Revit, primarily in XML or gbXML formats. gbXML is preferred for its user-friendliness and versatility, making it easier to share building data between architectural and engineering analysis tools [
71]. Ecotect can simulate energy use based on local weather conditions and building specifications, and provides visual and animated outputs, making the results more digestible for users [
73]. However, the software is known for its slow performance and an overly complex simulation engine that struggles to meet certain regulatory requirements [
66].
eQUEST is a free and user-friendly energy analysis tool that allows for rich graphical representations of energy simulations. It is well-suited for quick assessments of materials and energy use based on limited architectural input. Users can analyze energy-saving strategies, lighting systems, and estimate energy costs with eQUEST [
65]. However, the tool runs slowly and is limited in simulating natural ventilation or thermal comfort. Additionally, eQUEST imports via DWG files only produce 2D building energy data, limiting its comprehensiveness [
77].
3.3.2. Integration Framework Methodology and Integration Process
The integration of BIM software with LCA tools involves several methods to streamline the analysis of environmental impacts. The primary methods are:
Bill of Quantities (BOQ) Import:
Description: This method involves exporting a list of construction materials from the BIM software, which is then used for LCA calculations. The BOQ, generated automatically from the BIM model, is transformed into material and energy consumption data for analysis.
Example: Glodon was used to export the BOQ, translating BIM model geometry into material and energy data. Hollberg and Genova utilized Dynamo to connect the BIM model with LCA factors, improving data exchange efficiency [
9,
79].
IFC Import:
Using the BIM Viewer:
Using BIM Plug-ins for Direct LCA Calculation:
LCA Plug-in Calculation:
Each method has its strengths and limitations, with choices often depending on the specific needs of the project and the tools available.