Life Cycle Assessment in the Early Design Phase of Buildings: Strategies, Tools, and Future Directions

Abstract

The construction industry plays a significant role in global warming, accounting for 42% of primary energy use and 39% of greenhouse gas (GHG) emissions worldwide. Life Cycle Assessment (LCA) has emerged as a key methodology for evaluating environmental impacts throughout a building’s life cycle, yet its integration in the early design phase remains limited. This review aims to examine strategies and tools for incorporating LCA in the early design phase to enhance sustainability in building construction. The objectives of this study are: (1) to identify the main challenges in integrating LCA into early design workflows, (2) to analyze and compare LCA tools suitable for early-stage assessments, and (3) to explore emerging trends and technological advancements. A systematic literature review was employed using the Scopus database to analyze existing literature, identifying current practices, challenges, and technological advancements in early-stage LCA implementation. A total of 56 studies were identified for the review. The results highlight the growing adoption of Building Information Modeling (BIM), Artificial Intelligence (AI), and parametric modeling in streamlining LCA integration. Despite these advancements, barriers such as data scarcity, lack of standardization, and interoperability issues persist. Key findings suggest that simplified and computational LCA tools can improve accessibility and real-time decision-making during early-stage design. The study concludes that enhancing data availability, refining methodologies, and fostering collaboration between architects, engineers, and policymakers are crucial for mainstreaming LCA in sustainable building design. This review provides actionable insights to bridge the gap between sustainability goals and early-stage design decisions and framework, ultimately supporting a more environmentally responsible construction industry.

1. Introduction

Greenhouse gases (GHGs) are at the heart of global climate change discussions, as their accumulation in the atmosphere disrupts natural systems and accelerates global warming [1,2]. Carbon dioxide (CO₂), the most prevalent GHG, accounts for over 70% of all anthropogenic emissions [3]. Its sources include fossil fuel combustion, industrial processes, and land-use changes, with emissions rising steadily due to expanding urbanization and industrial activities [4,5]. The pressing need to address climate change has prompted over 130 countries and regions to set ambitious goals for “zero carbon” or “carbon neutrality” [6]. Many of these nations aim to reach carbon neutrality between 2050 and 2070 [7]. The Intergovernmental Panel on Climate Change (IPCC) recommends that to limit global warming to below 1.5 °C from pre-industrial levels by 2100, net human-induced CO₂ emissions must be reduced by 45% by 2030 and reach net-zero by 2050 [8]. The construction industry plays a significant role in global warming, accounting for 42% of primary energy use and 39% of worldwide GHGs emissions [9,10].

At the COP26 conference, more than 90% of the global GDP pledged to reach net-zero emissions. These pledged nations lead global investments in energy infrastructure and technological advancements, positioning them as pivotal players in the fight against climate change [11,12,13,14,15]. Buildings go through multiple phases throughout their lifespan, including preconstruction, construction, operation, maintenance, and demolition [16]. A report by the United Nations Environment Programme (UNEP) indicates that in 2020, the global construction sector was responsible for 37% of total carbon dioxide (CO₂) emissions. This included 27% from building operations and 10% from the production of building materials. Within the 27% attributed to building operations, 9% were direct emissions, while the remaining 18% resulted from indirect emissions linked to electricity consumption and commercial heating [17].

Life Cycle Assessment (LCA) is internationally standardized through frameworks such as ISO 14040/14044 and EN 15978, which define how environmental performance should be evaluated throughout a building’s life cycle [18,19,20,21,22]. LCA is a widely recognized method for quantifying environmental impacts associated with a product or system throughout its entire life cycle [23,24,25]. This includes all stages, from raw material extraction and manufacturing to usage and final disposal. LCA provides a comprehensive and systematic approach to evaluating environmental performance, supporting informed decision-making for sustainable resource management [26,27]. It is regarded as one of the most effective frameworks for assessing a product’s potential environmental footprint and optimizing its life cycle sustainability [28,29]. The built environment significantly contributes to GHG emissions, with two major contributors: operational emissions (OE) and embodied carbon (EC), as shown in Figure 1. Operational emissions (OE), also known as operational use emission and operational carbon, refer to the GHG emissions generated from energy consumption during a building’s operational phase, mainly for heating, cooling, lighting, and other energy-intensive activities. These emissions are primarily associated with fossil fuel consumption in HVAC systems, electrical appliances, and lighting [30,31,32]. One key strategy for minimizing OE is the adoption of passive design principles, which leverage natural ventilation, daylighting, and thermal mass to reduce reliance on mechanical heating and cooling systems [33]. Research indicates that passive solar heating can decrease heating energy demand by up to 40% in cold climates, demonstrating its potential as a low-cost and sustainable mitigation measure. A study by Sartori and Hestnes (2007) found that net-zero energy buildings (NZEBs) can achieve up to 80–100% reductions in operational emissions by combining energy-efficient design with on-site renewable energy generation [34].

Embodied carbon refers to the total CO₂ emissions associated with the extraction, manufacturing, transportation, installation, maintenance, and end-of-life disposal of building materials [35]. EC accounts for approximately 11% of total global energy-related CO₂ emissions and 28% of emissions in the building sector [36]. By 2050, it is estimated that embodied carbon will represent 50% of the total emissions from new constructions, as operational emissions decline due to improved energy efficiency and renewable energy adoption [37]. Concrete production alone is responsible for 8% of global CO₂ emissions, primarily due to cement, which contributes around 90% of concrete’s carbon footprint [38]. Steel production contributes 7–9% of global GHG emissions, with nearly 40% of steel demand coming from the construction sector [39]. A study analyzing residential buildings found that embodied carbon emissions range from 250–600 kg CO₂e/m², depending on material selection, construction techniques, and regional energy sources [40]. Buildings in Europe and North America tend to report lower embodied carbon intensities compared to global averages, typically ranging from 400–600 kg CO₂e/m². This can be attributed to factors such as stricter building codes, wider use of recycled materials, and the adoption of sustainable construction practices [41].

Integrating LCA in the early design phase is challenging due to limited data availability, lack of standardized methodologies, and the complexity of LCA tools [42,43]. Traditional LCA assessments require detailed material specifications, energy consumption data, and construction process inputs, which are often unavailable during the conceptual and schematic design stages [44]. Additionally, most existing LCA tools are designed for post-design or post-construction evaluations, making them less adaptable for real-time, early-phase decision-making [45]. Another critical barrier is the interoperability of LCA tools with Building Information Modeling (BIM) and parametric modeling software, as many LCA software lack seamless integration with commonly used architectural design platforms [46]. Furthermore, architects and designers may lack the expertise to conduct LCA analyses, as the process often requires advanced knowledge of environmental impact categories and complex data modeling. These challenges hinder proactive sustainability integration in the early stages of building design.

The World Green Business Council’s report, Bringing Embodied Carbon Upfront, highlights key strategies for minimizing embodied carbon emissions in the construction industry [47]. The most significant carbon reductions can be achieved during the early planning and design phases, where emissions can be reduced by 50% to 80% [48]. Insights from recent industry studies from HM Treasury and Green Construction Board, a whole-life carbon assessment approach suggests that early-stage decision-making is the most effective phase for reducing embodied carbon [49]. Despite the increasing emphasis on sustainability in architecture and construction, there is no universally accepted framework for conducting LCA in the early design phase [50]. One recent review (2021) underscored the need to address buildings’ life cycle impacts from the early design stages and noted that LCA, while beneficial, is often perceived as too complex to integrate into routine design workflows [51]. Similarly, Huang et al. (2025) classified early design LCA integration approaches into simplified, detailed, and incremental methods, finding that no single approach fulfills all design requirements and highlighting a lack of practical incremental LCA solutions in current practice [52]. Basbagill et al. (2013) took a more technical angle by introducing a BIM-based LCA method with sensitivity analysis to guide early-stage decisions, demonstrating how targeting high-impact material and component choices can yield significant reductions in a building’s embodied carbon [53]. Dalla Valle (2023) provided case-study evidence that conducting LCA during preliminary design (e.g., in architectural competitions using the Level(s) framework) helps pinpoint carbon-intensive building elements and inform low-carbon design solutions from the outset [54]. This review is motivated by the need to synthesize existing research on early-stage LCA implementation, compare different tools, and identify key findings from all selected studies to gather broader information about early design phases of buildings. Moreover, emerging technologies such as AI-driven LCA, digital twins, and parametric simulations offer new possibilities for integrating sustainability into early design, but their potential remains underexplored in academic literature [55].

This review aims to provide a comprehensive analysis of early design phase of building using LCA. The objectives of the study focus on strategies, tools comparisons for early-stage design, and emerging trends and technological advancements in early-stage LCA implementation. This review is guided by the central research question: How can LCA be effectively integrated into the early design phase of buildings to support sustainability-oriented decision-making? Supporting this, the review explores (1) the key challenges to early-stage LCA implementation, (2) the comparative effectiveness of available tools for early-stage assessment, and (3) emerging technological advancements such as AI, BIM integration, and parametric modeling in this domain. While previous studies have examined LCA in broader design and construction contexts [56,57,58,59,60], this review uniquely focuses on early-stage design phase integration, literature on AI-driven LCA, and parametric modeling approaches review, making it highly relevant for architects, sustainability researchers, and policymakers seeking to enhance sustainability-driven decision-making in building design.

The structure of this paper is as follows: Section 2 introduces the LCA of buildings and its stages. Section 3 outlines the methodology used for selecting and analyzing relevant literature. Given the review-based nature of this study, the discussion and interpretation of results are integrated directly into Section 4, following the content analysis, rather than presented in a separate discussion section. The final section summarizes key findings, outlines future research direction, and proposes recommendations for advancing early-stage LCA in architectural design.

2. Overview of LCA in Building Design

While the introduction established LCA as a key methodological framework for sustainability assessment, this section provides a more targeted overview of how it has been applied specifically in building design contexts, particularly focusing on scope types, system boundaries, and practical challenges. As per EN 15978:2011 [22], life cycle emissions are categorized into three main components: EC, OE, and impacts beyond the building life cycle, such as reuse, recovery, and recycling potential. The stages of LCA are shown in Figure 2. The stages of a building’s life cycle, as outlined in EN 15978, range from material production to end-of-life processes [61,62,63,64,65]. However, for early-stage LCA, the focus is generally limited to cradle-to-gate or cradle-to-site system boundaries, as detailed construction and usage data are not yet available during the initial design phases [12].

In the system boundary, cradle-to-gate LCA assesses the environmental impact from the extraction of raw materials (cradle) to the point where the product leaves the factory (gate). It excludes transportation, installation, use, maintenance, and disposal phases. Cradle-to-site LCA extends cradle-to-gate by including transportation emissions up to the construction site. However, it still excludes operational, maintenance, and end-of-life phases. WLCA is the most comprehensive approach, covering all life cycle stages of a building from raw material extraction (cradle) to construction, operation, maintenance, and end-of-life disposal (grave). It is important to note that EN 15978:2011, while still the current standard, is undergoing a significant revision. The forthcoming revision is anticipated to introduce clearer definitions for system boundaries and new reporting requirements, aiming to enhance the overall consistency and transparency of environmental assessments.

3. Materials and Methods

To enhance transparency and reproducibility, the methodological workflow of this review is structured into the following steps:

3.1. Research Scope and Literature Search Strategy

This review paper follows a structured approach to identify and analyze relevant literature on early-stage carbon dioxide emission assessment in building design using LCA. The study primarily relies on academic sources retrieved from the Scopus database, ensuring a high standard of peer-reviewed research, complemented by an additional search on Google Scholar. The articles and reports included in this review were gathered through a structured search methodology. The search process utilized a combination of keywords related to early-stage building construction and its CO₂ emissions impact from an LCA perspective. Boolean operators (AND, OR) were applied to refine the results and ensure the selection of pertinent studies. “LCA-EC” is first introduced in this paper and is not yet widely adopted. Furthermore, comprehensive relevant literature retrieval is built on LCA in building or construction. To encompass keywords relevant to LCA, the search terms include combinations of (“LCA” OR “-LCA” OR “life cycle assessment” OR “life cycle evaluation”) or (“carbon emission” OR “embodied carbon”). Terms related to “building” and “early-design stage” are further classified in

Table 1. Criteria for eligible literature through Scopus (excluded if not meeting these criteria).

No.	Criteria	Scopus
1	Search Terms	TITLE-ABS-KEY (((“LCA” OR “-LCA” OR “life cycle assessment” OR “life cycle evaluation” OR “Embodied Carbon”) AND (“Building” OR “Construction”) AND (“Early-stage” OR “Early-design” OR “Earlydesign” OR “stage of design” OR “design-stage”)))
2	Publication Years	2015–2024
3	Document Type	Article
4	Language	English
5	Database	Scopus database
6	Irrelevant Disciplines	Subject Categories retrieved excluding:
		Pharmacology, toxicology, and pharmaceutics;
		Physics and Astronomy;
		Chemical Engineering;
		Computer Sciences;
		Economics, Econometrics, and Finance;
		Biochemistry, Genetics, and Molecular Biology;
		Decision Sciences
		Pharmacology, toxicology, and pharmaceutics;

(Criteria No. 1). The specific search query used was TITLE-ABS-KEY (((“LCA” OR “-LCA” OR “life cycle assessment” OR “life cycle evaluation” OR “Embodied Carbon”) AND (“Building” OR “Construction”) AND (“Early-stage” OR “Early-design” OR “Earlydesign” OR “stage of design” OR “design-stage”))) conducted on 8 January 2025. The search was restricted to publications written in English language and limited to open-access sources. The search period was limited to 2015–2024 to focus on recent advancements in digital tools (e.g., BIM, AI, parametric modeling) and sustainability practices, which have evolved significantly over the past decade. This timeframe ensures that the review reflects the latest trends and methodological developments in early-stage LCA applications.

3.2. Initial Screening and Eligibility Criteria

As shown in Figure 3, 231 articles were retrieved using specific keywords and Boolean operators in Scopus database, ensuring their relevance to early-stage building design and carbon emission assessment.

The screening process began with the exclusion of 107 records, including articles that were not in English, review papers, or early-access publications, reducing the count to 124 unique articles. In the screening phase, 68 peer reviewed journal articles were excluded since they were from disciplines which are not relevant to our study, further narrowing the selection to 63 papers for detailed evaluation. During the eligibility stage, only manuscripts which were open-access were considered to verify the methodological rigor and relevance of each study about LCA in early-stage building design. As a result, 7 papers were excluded due to a lack of focus on LCA methodologies, leading to the final inclusion of 56 studies.

3.3. Full-Text Review and Final Selection

A total of 56 studies were selected for full analysis following a comprehensive eligibility check. These selected studies form the foundation of this review, offering valuable insights into LCA methodologies, sustainability strategies in early design phases, and assessment of carbon emissions in building construction. In addition to synthesizing findings from these studies, this review employs bibliometric analysis to map research trends, identify influential works, and analyze the evolution of LCA research in the early design phase.

3.4. Data Extraction and Organization

A content analysis was performed by systematically extracting key information from each of the selected studies. The extracted data included the study title, publication year, and country of origin, main research objectives, defined system boundaries for the LCA (e.g., cradle-to-gate, cradle-to-site), tools or software used in the analysis, and the key findings related to early-stage LCA implementation. Given the review-based nature of this study, the discussion and interpretation of results are integrated directly into Section 4, following the content analysis, rather than presented in a separate discussion section. This structured data extraction enabled facilitated comparative evaluation across different methodological approaches, geographical regions, and technological applications. The results of this analysis are presented in Supplementary Materials. By combining these analytical approaches, this study not only builds upon previous reviews but also systematically evaluates knowledge gaps, enabling a more structured and comprehensive understanding of early-stage LCA applications in sustainable building design. The findings from these studies enable a comprehensive analysis of research trends, challenges, and opportunities in integrating LCA into early-stage of building design.

3.5. Bibliometric Analysis

For the bibliometric analysis, this study utilized VOSviewer software in conjunction with the Scopus database. VOSviewer was employed to generate visual bibliometric maps [66,67], illustrating the co-occurrence of keywords and emerging research trends in literature related to LCA and the early design phase of building construction. The bibliographic data was sourced from the Scopus Core Collection database and analyzed using VOSviewer to create graphical representations of keyword co-occurrence maps. The generated co-occurrence map identified frequently appearing keywords such as “LCA”, “Early-design building construction”, and “CO₂ Emission”, where node sizes represented keyword frequency, and connections indicated their co-occurrence relationships. This visual representation facilitated a comprehensive understanding of key trends, thematic relationships, and research gaps, thereby serving as a valuable foundation for identifying dominant themes and advancing knowledge in the field.

4. Results and Analysis

4.1. Bibliographic Analysis of the Existing Literature

A VOSviewer analysis of the 56 selected articles identified clusters of key terms and their interconnections, as illustrated in Figure 4. In this visualization, the circle sizes indicate the frequency of keyword occurrences, while the thickness of the connecting lines represents the strength of their relationships within the network.

The VOSviewer keyword network visualization represents the research landscape of LCA in the sustainable development, clustering frequently occurring keywords based on co-occurrence strength and interconnections [68,69]. The larger nodes indicate high-frequency keywords, with “life cycle assessment”, “life cycle”, “BIM”, and “sustainable development” being the most dominant research themes, highlighting the central focus on sustainability and environmental assessment in building studies.

The color-coded clusters represent distinct research domains within LCA. The blue cluster, centered around “life cycle assessment” and “building information modeling (BIM)”, suggests a strong focus on digitalization and LCA integration within BIM workflows. The green cluster, containing keywords such as “geopolymers”, “inorganic polymers”, and “acidification”, indicates research into low-carbon materials and alternative building solutions. The red cluster, linking “sustainable development”, “ecodesign”, and “energy utilization”, emphasizes studies on early-stage design strategies and energy efficiency. Meanwhile, the yellow cluster, with terms like “carbon emissions”, “carbon capture and utilization”, and “deep uncertainties”, reflects ongoing discourse on carbon footprint reduction and uncertainty analysis in LCA applications.

The network density and thickness of connecting lines illustrate strong interdependencies between sustainable design, material selection, and environmental impact assessment methodologies. The presence of peripheral terms such as “3D printing”, “climate change”, and “major building material” suggests emerging trends in additive manufacturing, climate resilience, and material innovation in LCA research. This visualization highlights that LCA research is evolving toward data-driven, technology-integrated approaches, with growing attention to embodied carbon assessment, material innovations, and energy-efficient strategies.

Among the 56 selected publications, three top key journals are Buildings (6), Sustainability (10), and Energy and Buildings (8) stand out in LCA research. Buildings (MDPI) focuses on sustainable architecture and BIM-integrated LCA, while Sustainability (Switzerland) covers LCA in construction, material efficiency, and policy-driven sustainability. Energy and Buildings (Elsevier) emphasizes energy performance, carbon footprint reduction, and renewable energy integration. Their combined presence highlights the interdisciplinary role of LCA in advancing sustainable building design.

The geographical distribution of publications shown in Figure 5a indicates that the United Kingdom, Italy, and China are the leading contributors to LCA research in the built environment, reflecting their strong focus on sustainable construction, energy efficiency, and policy-driven environmental impact studies. Other countries such as Belgium, Germany, and Spain also show significant contributions, indicating the growing global interest in integrating LCA methodologies into building design and urban planning. The temporal analysis of publications over the years 2015–2024 shows a steady increase in research output shown in Figure 5b, with notable peaks in 2018, 2021, and 2022. The sharp rise in publications post-2020 highlights the growing urgency of sustainability and carbon reduction strategies in construction, possibly influenced by global climate policies and advancements in LCA tools. The fluctuating trend suggests periodic surges in research interest, likely driven by policy updates, technological advancements, and funding availability for sustainability studies. These insights emphasize the evolving nature of LCA research and its increasing relevance in shaping sustainable building practices worldwide.

4.2. Content Analysis and Thematic Synthesis

To improve readability and streamline the presentation of results, the detailed overview of the 56 analyzed studies has been moved to Table S1 in the Supplementary Materials. Given the volume of information, a summarized synthesis is provided in the main manuscript to highlight the most prominent themes and patterns identified across the literature. The majority of studies adopted a cradle-to-gate system boundary, reflecting the practical limitations of early design phases where data on construction, operation, and end-of-life stages are typically unavailable [70,71,72,73]. Regarding tool usage, One Click LCA and Tally emerged as the most commonly applied platforms, often used in conjunction with BIM environments to enable material quantity take-offs and early carbon estimation [74,75,76,77,78]. Several studies also explored the integration of parametric design tools and AI-driven workflows, signaling a growing trend toward automation and scenario-based analysis in LCA [73,79,80,81]. Recurring challenges reported across the literature include the difficulty of applying detailed LCA methods during the early design stage, the lack of standardized datasets, and limited interoperability between digital tools and LCA software. Based on the patterns identified in the literature, several recurring themes emerged related to tools, methodologies, and implementation challenges. These are explored below and further interpreted in the context of the study’s research questions.

4.3. Addressing the Research Questions

This section synthesizes the key findings of the selected literature review, addressing the challenges, tools, and emerging trends related to LCA in the early design phase of buildings. The following synthesis addresses the three core research questions that guided this review, drawing directly from the patterns observed across the analyzed studies. First, this section examines the challenges associated with integrating LCA into early design workflows, including issues related to data availability, interoperability with design tools, and standardization gaps. Next, a comparative evaluation of LCA tools is presented, focusing on their suitability for early-stage assessments based on factors such as usability, integration with BIM, and effectiveness in rapid decision-making. Finally, emerging trends and technological advancements such as AI, parametric modeling, and cloud-based LCA solutions are explored, highlighting their transformative potential for early-stage building design. By addressing these aspects, this section identifies critical barriers, highlights best-suited tools, and outlines future directions for advancing the role of LCA in sustainable architectural practices. By addressing these aspects, this discussion highlights critical barriers, identifies best-suited tools, and outlines future directions for advancing the role of LCA in sustainable architectural practices.

4.3.1. Addressing the Challenges of Early-Stage LCA Implementation

There is a growing body of literature highlighting the challenges associated with implementing LCA in the early design phases of buildings. Studies indicate that early-stage LCA often lacks precise material specifications, leading to reliance on generic databases or assumptions that may not reflect actual project conditions [71], and early-stage EC calculations frequently depend on average material coefficients due to the absence of manufacturer-specific data, resulting in high variability and uncertainty in outcomes [82]. Additionally, scaling laboratory-scale data to industrial applications poses methodological concerns, as seen in thermochromic VO₂ window research where variations in process efficiency and material durability influence environmental impact assessments [83]. The lack of integration and standardization across different LCA methodologies, including varied boundary conditions, functional units, and impact categories, further complicates benchmarking and comparability [76,84]. Moreover, the limited availability of region-specific Environmental Product Declarations (EPDs) and material databases contributes to incomplete assessments and potential inaccuracies, as many commercial databases rely on average datasets or secondary data rather than localized, high-resolution inputs. This limitation makes it challenging to conduct precise environmental impact assessments that reflect region-specific material compositions and supply chain variations. Interoperability issues between BIM and LCA tools stem from differences in data granularity, format incompatibilities, and the lack of standardized exchange protocols, making it difficult to seamlessly integrate sustainability assessments into existing workflows [85], even though research suggests that integrating LCA within BIM can streamline data acquisition and reduce human error [78]. However, practical implementation remains hindered by software compatibility issues and differences in data granularity [86]. To mitigate these challenges, several innovative approaches are being explored. Natural Language Processing (NLP)-based semantic model healing and machine learning techniques help improve data accuracy by automatically identifying and correcting inconsistencies in BIM-LCA integration, reducing manual intervention and errors [73].

Additionally, parametric computational screening-LCA tools enable comparative environmental assessments even in the absence of precise material specifications, allowing designers to evaluate multiple design scenarios quickly and make informed sustainability decisions in early stages [80] Furthermore, Monte Carlo simulations aid in uncertainty quantification by assessing variability in input data, helping to address the limitations of incomplete datasets and improve the reliability of LCA results [75]. Also, procurement strategies such as design and build or two-stage early contractor involvement (2S-ECI) can significantly influence the integration of LCA in early design. These approaches promote earlier collaboration among stakeholders, enabling better access to supply chain data, material options, and constructability input. This, in turn, can reduce uncertainty in early-stage environmental assessments and enhance the practical application of LCA insights during conceptual design. There is growing recognition of the need to address the trade-off between embodied and operational energy, where focusing on reducing embodied carbon might inadvertently increase consumption, thereby necessitating multi-objective optimization strategies [87]. In response, streamlined LCA approaches are being developed to focus on key environmental hotspots such as high-impact materials, structural elements, and dominant energy-consuming components while optimizing computational efficiency to allow rapid sustainability assessments in the early design phase [5]. The integration of circular economy principles emphasizes material reuse, recyclability, and life cycle extension strategies to reduce embodied carbon and overall environmental impact throughout a building’s lifespan. Data-driven prediction models leveraging machine learning and big data analytics are being explored to enhance LCA accuracy by forecasting environmental impacts based on historical datasets and real-time project parameters, helping designers make informed sustainability decisions at the conceptual stage [88]. Despite these advancements, industry-wide adoption remains slow due to limited technical expertise and a lack of regulatory incentives, highlighting the urgent need for enhanced training programs, stronger legislative support, and user-friendly software solutions to fully integrate LCA into early design decision-making [89,90].

In early-stage design, practitioners often lack access to specific product or material details, making the use of EPDs impractical or methodologically inappropriate. Several studies have highlighted this challenge and emphasized the reliance on generic or average datasets to approximate environmental impacts [91,92,93]. These datasets are typically drawn from regional databases or pre-compiled typologies based on building archetypes. While they cannot capture product-specific variations, they allow for comparative decision-making across design alternatives in conceptual phases [94]. Röck et al. (2018) [91], for example, underline that simplified BIM-integrated LCA tools often default to average impact values for materials due to the low LOD of early models. Similarly, Hollberg and Ruth (2016) note that parametric design tools must accommodate uncertainty by working with generalized impact factors [46]. These practices reflect a pragmatic balance between data availability and design-time responsiveness, and underscore the importance of transparency in assumptions and data source selection during early-phase assessments. It is also important to recognize that LCA represents only one of several key performance criteria considered during early design. Architectural decision-making at the conceptual stage must also account for structural feasibility, building physics, fire safety regulations, daylight and ventilation goals, material availability, and cost constraints [33,35]. This multidimensional nature of early design often results in trade-offs, where environmental performance must be balanced with functional, regulatory, and technical priorities. Passoni et al., (2022) [95], emphasize that the integration of LCA into design workflows is most effective when embedded into multi-criteria decision-making frameworks, which allow for simultaneous assessment of environmental, structural, and user-related factors.

4.3.2. Comparison of LCA Tools for Early-Stage Assessments

LCA tools play a crucial role in evaluating the environmental performance of buildings, especially during the early design stages, enabling informed decisions to mitigate environmental impacts (shown in Table 2). BIM integration streamlines data collection for LCA by registering detailed object information such as material properties in a 3D modeling environment. While BIM-based LCA tools offer greater time efficiency compared to standalone tools, they still rely on advanced plans and detailed information [59,96,97]. There are several approaches to achieve BIM-LCA integration, such as adding environmental data to the BIM model, extracting information like the Bill of Quantities (BoQ) from the model, importing geometry into LCA software using IFC (Industry Foundation Classes) for data exchange, using an intermediate “viewer” in a 3D environment to match IFC information with environmental data and employing an “LCA plugin” for BIM software to provide a 3D environment for matching and visualizing results [98,99,100]. The “enriched BIM” approach, where LCA information is added to the model, reduces manual attribution and human error, centralizing data in the model and benefiting future uses like facility management. The most common approach is the “quantity take-off” method, where the BoQ is exported from the BIM model and connected to LCA software, which can make iterative design difficult due to manual processes [70,101,102,103].

A variety of software programs are available for conducting LCA, including SimaPro, BEES (Building for Environmental and Economic Sustainability), Tally (a BIM plugin), Athena Impact Estimator, One Click LCA, and Open LCA. Some tools like One Click LCA and Structural Carbon Tool are able to assess embodied carbon. Autodesk Revit is the most used tool by researchers, supported by plugins and APIs like Tally, simplifying environmental assessments directly within the BIM environment. Tools like the Carbon Planning Tool and Carbon Emissions Calculator are available, with reviews provided in the literature. BREEAM (Building Research Establishment Environmental Assessment Method) recognizes certain building LCA tools. Several tools integrate BIM with LCA for early design stages, such as BIM Integrated Assessment, Integrated Dynamic Model (BIM), BIM-based LCA through visual programming (e.g., One Click LCA) and Extended BIM Ontology. Screening LCA is suited for the pre-design or concept phase, while simplified LCA is applied in detailed design phases. Screening LCA uses a generic LCA database of building materials and focuses on manufacturing and transportation emissions, with GWP as the impact indicator. Simplified LCA approaches often focus on the embodied impact assessment of materials and integrate BIM with other tools to translate technical drawings into a bill of materials. Parametric tools aid in assessing operational energy use, embodied energy, and embodied material emissions in buildings.

Despite the benefits, there are challenges and considerations in using LCA tools. Complexity and time consumption are barriers to LCA [104]. A key challenge is achieving interoperability between BIM software and EC assessment tools [105]. The choice of LCA database is fundamental and should relate to the building site, local market, and materials. Different LCA databases (e.g., Ecoinvent, ICE) can yield varying results [106]. Simplified LCA can lead to uncertainties about the consistency and representativeness of results [107,108]. A lack of available LCA software integrated into BIM tools is a problem, though integration simplifies execution [109]. The calculation engine is less relevant than the databases and simplifications that influence decision-making in building design [110]. Data gaps and the absence of detailed material specifications can create uncertainty, particularly in early design stages [104]. Visualizing LCA results directly in the BIM model enhances transparency and supports an iterative design process [111].

Table 2. LCA tools for early-stage assessments.

Tool/Approach	Description	Key Features	References
Simplified LCA tools	Focus on the most influential elements and decisions, providing a practical solution for early design.	Easy to use; facilitates holistic evaluation of environmental sustainability with LCI data collection.	[107,108,112,113,114]
BIM-integrated LCA	BIM solutions with integrated LCA offer a promising approach for early design stages.	Speeds up the simplified LCA process using a BIM-based quantity take-off (QTO) approach; provides information consistent with low Level of Development (LOD).	[70,102,105,111,115]
Screening LCA	Suited for the pre-design or concept phase.	Uses a generic LCA database of building materials; focuses on manufacturing and transportation emissions; uses GWP as the impact indicator.	[71,116,117,118,119]
Parametric LCA	Useful for users without LCA expertise.	Allows users to get results regarding the environmental performance of their designs.	[49,68,103]
Computational screening-LCA tools	These tools simplify the LCA of buildings for the early design stages.	Allows users to select different construction systems and materials to compare their GWP impact.	[5,73,80,95,120,121]
One Click LCA	Cloud-based LCA software.	Used by building sector professionals to evaluate the carbon impact of projects; compatible with many green building certification schemes.	[75,76,77,122]
Tally	Plug-in for Revit.	Automatically extracts building information within the same software to conduct LCA.	[78,111,122]
SimaPro	LCA software	Can adopt additional data by different databases or EPDs. Extensively adopted thanks to the availability for many platforms and tools.	[102,123,124,125,126]
LCA for Experts (GaBi)	LCA software	Used to produce 1 m3 of geopolymer binder for 3D-AM. Calculates potential impact indicators by characterisation.	[127,128,129,130]
PANDA	Embodied carbon software	Helps in early-stage design selection and can significantly lower the final carbon footprint of realized projects. Designs guided by PANDA correlate with lower embodied carbon, linked to avoiding high-intensity projects and selecting lower-carbon materials.	[4]
OpenLCA	LCA software	OpenLCA is a software used for LCA. Open access to LCA calculations improves transparency and readability. Can adopt additional data by different databases.	[76,131]

Table 2. LCA tools for early-stage assessments.

Tool/Approach	Description	Key Features	References
Simplified LCA tools	Focus on the most influential elements and decisions, providing a practical solution for early design.	Easy to use; facilitates holistic evaluation of environmental sustainability with LCI data collection.	[107,108,112,113,114]
BIM-integrated LCA	BIM solutions with integrated LCA offer a promising approach for early design stages.	Speeds up the simplified LCA process using a BIM-based quantity take-off (QTO) approach; provides information consistent with low Level of Development (LOD).	[70,102,105,111,115]
Screening LCA	Suited for the pre-design or concept phase.	Uses a generic LCA database of building materials; focuses on manufacturing and transportation emissions; uses GWP as the impact indicator.	[71,116,117,118,119]
Parametric LCA	Useful for users without LCA expertise.	Allows users to get results regarding the environmental performance of their designs.	[49,68,103]
Computational screening-LCA tools	These tools simplify the LCA of buildings for the early design stages.	Allows users to select different construction systems and materials to compare their GWP impact.	[5,73,80,95,120,121]
One Click LCA	Cloud-based LCA software.	Used by building sector professionals to evaluate the carbon impact of projects; compatible with many green building certification schemes.	[75,76,77,122]
Tally	Plug-in for Revit.	Automatically extracts building information within the same software to conduct LCA.	[78,111,122]
SimaPro	LCA software	Can adopt additional data by different databases or EPDs. Extensively adopted thanks to the availability for many platforms and tools.	[102,123,124,125,126]
LCA for Experts (GaBi)	LCA software	Used to produce 1 m3 of geopolymer binder for 3D-AM. Calculates potential impact indicators by characterisation.	[127,128,129,130]
PANDA	Embodied carbon software	Helps in early-stage design selection and can significantly lower the final carbon footprint of realized projects. Designs guided by PANDA correlate with lower embodied carbon, linked to avoiding high-intensity projects and selecting lower-carbon materials.	[4]
OpenLCA	LCA software	OpenLCA is a software used for LCA. Open access to LCA calculations improves transparency and readability. Can adopt additional data by different databases.	[76,131]

4.3.3. Emerging Trends and Technological Advancements in Early-Stage LCA

Recent advancements in early-stage LCA involve a significant trend toward integrating BIM to evaluate environmental impacts during initial design phases, which accelerates analysis and enhances cost-effectiveness through automated quantity take-off for whole-building LCA [70,102,105,111,115]. Simplified approaches, such as parametric LCA, are also emerging to broaden participation without requiring specialized expertise [49,68,103,128]. The construction industry is experiencing a digital transformation with increasing automation and digital marketplaces for reclaimed materials. Adopting Life Cycle Thinking (LCT) from the start of design promotes sustainable renovation by allowing early evaluation of design alternatives. Emerging technologies such as digital twins offer enhanced data management and transparency for material reuse [117,118]. Artificial intelligence (AI) improves data accuracy and enables early approximations of embodied GHG emissions through machine learning (ML) algorithms [5,73,80,95,121,128].

4.3.4. Key Findings and Framework

A crucial finding is that BIM adoption correlates with sustainability in smaller construction projects, allowing for optimized early-stage design [115]. Also, integrating life cycle carbon emission calculations early in the design phase can lead to savings in time and labour [108,129]. Aligning LCA with BIM-based Level of Development (LOD) stages allows the assessment to adapt to the level of available detail. Early stages (LOD 100–200) rely on assumptions, while advanced stages (LOD 300–400) enable detailed, material-specific evaluations and procurement-level analysis [105,111]. Studies also emphasized the importance of LOD in determining the feasibility and accuracy of early-stage LCA [115]. At lower LOD levels, particularly LOD 100–200, which correspond to conceptual and schematic design phases, models typically lack detailed specifications on materials, quantities, and construction assemblies. This lack of granularity introduces significant uncertainty into LCA outputs, often requiring reliance on generalized assumptions, benchmark data, or standard archetypes [130,131]. As BIM models progress to LOD 300–350, the availability of more specific geometric and material information enhances the capability for conducting more accurate and scenario-specific impact assessments. At LOD 400 and above, the integration of fabrication and construction-level detail enables high-resolution LCA suitable for procurement planning and certification alignment. Engagement with stakeholders, the development of structured BIM protocols, and the reassessment of new designs from a life cycle perspective all represent potential topics of future study [74]. This review contributes to closing a specific gap in the literature by focusing on early-stage LCA integration in building design, with particular attention to underexplored digital innovations that can support real-time, low-data decision-making.

Framework aims to visually and structurally summarize key insights from the literature, offering a conceptual guide for integrating LCA into early-phase building design. Based on the thematic synthesis of the 56 selected studies, this section presents a conceptual framework that consolidates the recurring patterns, tool integrations, and methodological gaps identified throughout the literature. The framework is not a novel methodology proposed by the authors, but rather a visual and structural synthesis developed from the findings of the literature review. It aims to guide practitioners and researchers in understanding how Life Cycle Assessment (LCA) can be effectively integrated into early-phase building design processes.

The framework is built upon four core dimensions observed across the literature:

(1)

the timing and type of LCA integration in the design workflow,

(2)

the selection and compatibility of digital tools (e.g., BIM, parametric design, AI-enhanced systems),

(3)

typical system boundaries and data limitations at early stages, and

(4)

the decision-making environment, including trade-offs and sustainability objectives.

Figure 6 illustrates this conceptual framework, showing how these elements interact within a typical early-stage design process. This model serves as a summarizing tool to reflect key literature insights, and may inform both academic research and practical implementation strategies going forward. The process begins with the conceptual design stage, where an initial LCA evaluation is conducted to assess the environmental impact of preliminary design choices. This is followed by the design development phase, where LCA findings guide the formulation of impact reduction strategies, helping designers make informed material and energy-efficient decisions. As the project progresses into the design refinement stage, a detailed LCA report is generated to provide an in-depth assessment of the building’s embodied and operational carbon footprint. The pre-construction planning phase involves a construction LCA review, ensuring that sustainability strategies are upheld in material procurement and construction methodologies.

Finally, the Construction and Execution stage marks the transition to the operational phase, where LCA insights contribute to performance monitoring and long-term sustainability goals. This structured approach ensures that LCA is systematically integrated into early-stage decision-making, facilitating data-driven design optimizations and fostering environmentally responsible construction practices.

5. Conclusions and Outlook

This review has systematically examined the role of LCA in the early design phase of buildings, addressing key research questions regarding its challenges, tools, and emerging trends. This review adds to the existing body of knowledge by systematically examining early-stage LCA integration and synthesizing developments in AI, BIM, and parametric tools, offering a practical and forward-looking framework for sustainable design. The findings highlight that while LCA is a valuable tool for reducing the environmental impact of construction, its early-stage implementation faces significant barriers, including limited data availability, methodological inconsistencies, and the complexity of integrating LCA tools into conventional design workflows. The implications of these findings suggest that advancements in digital technologies, such as BIM and Digital twins, offer promising solutions to enhance the feasibility and accuracy of early-stage LCA. The growing adoption of parametric modeling further enables designers to assess multiple design alternatives quickly, leading to more informed and sustainable decision-making. However, these tools require better interoperability, user-friendly interfaces, and standardized methodologies to ensure broader industry adoption.

A key recommendation for improving early-stage LCA integration is the incorporation of Level of Development (LOD) in BIM workflows. LOD enhances early-stage LCA by defining the detail and accuracy of BIM components at different design phases. At LOD 100-200 (conceptual design), simplified LCA relies on assumptions and benchmarks, while LOD 300-350 allows more precise material-based impact assessments. At LOD 400+, highly detailed LCA supports procurement and sustainability certification. By aligning LCA with LOD progression, early-stage decision-making becomes more data-driven, reducing uncertainties and optimizing environmental performance.

Future research should focus on refining LCA methodologies to incorporate real-time data inputs, exploring how circular economy principles can be more effectively integrated into early design assessments, and developing standardized frameworks that accommodate diverse construction practices across different regions. Additionally, long-term studies evaluating the actual impact of early-stage LCA decisions on building performance and carbon footprints are needed. Integrating LCA into early design holds great potential to advance sustainable construction practices. By addressing existing challenges, enhancing digital tool capabilities, and fostering interdisciplinary collaboration, the construction industry can move towards more environmentally responsible and resource-efficient building practices.

6. Limitations of the Study

While this review provides a comprehensive synthesis of recent approaches to integrating LCA in early-stage building design, certain limitations should be acknowledged. First, the literature search was limited to publications in English, which may have excluded relevant studies published in other languages, especially those from non-English speaking countries with active sustainability research agendas. Second, the review focused on literature published between 2015 and 2024 to capture recent developments in digital tools and early-stage LCA methods; however, extending the timeframe could have uncovered foundational or historical insights. Third, the use of Scopus as the primary database, although comprehensive, may have excluded studies that are indexed only in other academic repositories. Additionally, while this study aims to present generalized themes, regional policies, building codes, and tool availability may influence the local applicability of the findings. Finally, the proposed framework is based on literature synthesis and has not yet been validated through empirical testing or real-world case studies, which represents an opportunity for future research.