Digital Inventories for Circular Design: Solutions for the Built Environment

Abstract

Despite growing efforts to promote circular design in the built environment—supported by recent EU directives and digital innovation—the implementation of such strategies remains limited by a critical gap: the lack of reliable, structured, and accessible data on existing buildings. Although well-established in cultural heritage management, traditional inventory methods are not fully leveraged in the construction sector to support circularity. Furthermore, while Digital Twins offer the potential to address data-related challenges, their adoption is fragmented and hindered by the absence of standardised protocols and integration mechanisms. To address this gap, this paper examines the role of digital inventories in the built environment as valuable tools for promoting circular design in alignment with circular economy principles. It addresses the evolution of traditional inventories into advanced databases, emphasising their importance for informed decision-making, particularly in light of the European Commission’s emission reduction targets for the building sector. The study defines the concept of ‘digital inventory’ by analysing differences and overlaps between similar concepts used in the built environment. Through a bibliometric analysis, the research systematically organises the state of the art on the topic, identifying four main clusters to group the selected documents based on their focus. Ultimately, it analyses and compares examples of platforms for circular economy. The study concludes by advocating for open, updatable digital inventories to facilitate the integration of circular design practices within the construction industry, contributing to sustainable development in the built environment.

1. Introduction

In cultural heritage management, inventories play a central role in conserving and maintaining heritage sites. A fundamental principle underpinning this practice is that ‘one must know what heritage exists to manage it’ [1]. Traditionally, inventories were static lists of items; however, they have evolved into more dynamic formats, such as databases and Geographic Information Systems (GIS) [2]. These advancements improved the documentation process, showing that the digital version of traditional inventories represents a successful method of dealing with the built environment.

The importance of inventories extends beyond cultural heritage and offers substantial potential for the construction industry, particularly in transitioning towards circularity. Recognising and managing the existing built environment through systematic inventories can support the reuse and recycling of building components, aligning with Circular Economy (CE) principles. For instance, inventorying buildings is crucial for reuse as it identifies valuable materials and components, reduces waste, and supports sustainable construction practices by maximising the life cycle of existing resources [3].

In recent years, the application of circular design in the construction sector has gained momentum, mainly due to legislative support from the European Commission. Notably, the revised Energy Performance of Buildings Directive (EU/2024/1275) and the revised Energy Efficiency Directive (EU/2023/1791) aim to achieve an emission reduction of at least 60% in the building sector by 2030 and a zero-emission building stock by 2050 [4].

Despite these efforts, a significant barrier to implementing circular practices is the absence of reliable, structured, and accessible data on the existing building stock. Such a data gap hinders digitalisation processes and creates inefficiencies in collecting, verifying, and validating necessary information. Within this context, the key is the development of comprehensive inventories that capture and organise data from the outset, ensuring long-term accessibility for future analyses, planning, and circular strategies.

Even though concepts like Digital Twins (DTs) have been proposed as a promising approach to enhance data availability and utility in heritage and contemporary building sectors, their current application remains limited and fragmented. Challenges include a lack of interdisciplinary integration and standardised protocols for generating, managing, and synchronising the digital counterpart of physical assets [5]. Within this context, an important research gap refers to the absence of an overview of possibilities, perspectives, and holistic integration, collecting applicable concepts from different domains that could contribute to the definition of the “digital inventory for circular design” concept.

Hence, this study aims to explore the evolving role of inventories in the digital transformation of the built environment. It contributes to the research by investigating how digital inventories—defined here as dynamic, open, and updatable systems—can serve as foundational tools for implementing circular design strategies. Thus, it proposes a conceptual and practical framework for leveraging digital inventories to support sustainable and circular approaches in building management, thus laying the groundwork for more integrated and efficient systems in the future. The specific objectives of the paper are the following:

• Define the concept of digital inventory by combining aspects from several built environment-related domains and highlighting overlaps and contrasts between them;
• Conduct a meticulous and comprehensive literature review and bibliometric analysis focusing on the intersection of the concepts previously identified;
• Study and compare existing web-based platforms for CE against selected criteria, such as data integration capabilities and scalability.

The paper is structured as follows. Section 2 presents the study’s methodological framework, clarifying the different stages involved. Section 3 defines the digital inventory concept from the authors’ perspective, combining terms deriving from different research areas. This section maps out the eventual overlaps and contrasts between these concepts, discussing their possible integration. Section 4 includes the bibliometric and scientometric analysis, which was developed to capture the publications combining the terms and domains identified in Section 3. The extracted and evaluated data on the selected publications refer to time evolution; geographic distribution; type of publication; disciplinary field; authors and co-authorship network; and co-occurrence network of keywords. Section 5 presents the four main clusters identified through the systematic review, where the relations between inventories and the most recurrent keywords (circular economy—Section 5.1, architectural design/construction industry—Section 5.2, digital twins—Section 5.3, and sustainable development—Section 5.4) are discussed in detail. Based on the reflections from the analysis in Section 5.1, the authors decided to analyse and compare eight existing web platforms for circular economy through selected assessment criteria (Section 6). Section 7 concludes the paper by discussing research topics, potentials, limitations, challenges, and future perspectives.

2. Materials and Methods

This section describes the methodological framework (Figure 1), which is divided into four main stages:

• Definition of the digital inventory concept, identifying and analysing the most relevant keywords used to describe and represent various information repositories for the built environment, highlighting their differences and overlaps;
• Literature review and analysis, including a bibliometric analysis and a topic analysis focusing on four main aspects when dealing with inventories, given the context identified in the first stage;
• Analysis of example web-based platforms for CE;
• Critical review of the information collected and discussion on current and further research.

Figure 1. Methodological framework of the paper.

Figure 1. Methodological framework of the paper.

More specifically, stage 1 includes a detailed and critical analysis of the research topics highlighted to group similar aspects of dealing with inventories or repositories in the built environment from different domains. The questions that inspired this discussion are “What are the contents of a digital inventory for circular design? Which information should they contain? Which digital technologies should be used?”

Stage 2 includes the bibliometric and scientometric analysis, which follows the roadmap depicted in Figure 2, and the topic analysis, where the four clusters identified through the analysis of the co-occurrence network of keywords are discussed. The results from the keywords selection in the previous stage helped to organise the state of the art of the scientific literature systematically, focusing on the intersection of digital inventories, built environment, and CE. The database used for the search was Scopus. This choice was made due to Scopus’ broad journal coverage and faster citation analysis, and to it including more articles than Web of Science [6]. Therefore, Scopus covers the area of engineering [7] very well, reporting a higher number of papers than Web of Science [8]. Additionally, Scopus delivers the fewest inconsistencies in terms of content verification and content quality [9]. The keywords identified in Section 3 prompted the query for the data search. The following data were extracted: number of documents, types of publications, distribution of publications per year, distribution by country, authors, subject area, and keywords used. Data were evaluated using spreadsheets produced in Microsoft Excel 2016 and bibliometric networks created with VOSviewer 1.6.20. Further details on the bibliometric and scientometric analysis are given in Section 4.

Stage 3 describes, compares, and categorises eight web-based platforms for CE to show the different approaches and strategies. After the literature review analysis during stage 2 of the methodology, the authors added this part due to the high relevance that such web platforms have gained in recent years, as highlighted in Section 5.1. The authors selected platforms they considered relevant for this kind of analysis, including both mature platforms (in terms of time evolution and technological maturity) and emerging ones, but also based on their relevance in the different geographic areas.

Stage 4 includes a critical discussion highlighting the main strengths, weaknesses, and future challenges of implementing digital inventories to deal with the built environment from a circular practice perspective.

3. Defining the Digital Inventory Concept

The optimisation of data capture and processing has laid the foundation for several methodologies developed for the built environment over the years [10]. Digital tools help achieve an updated and deeper understanding of buildings, increasing their value [11]. Even though past research has extensively analysed the combination of concepts related to the built heritage and their digital counterparts [12,13,14,15,16,17], a lack of integration among the various definitions and concepts persists. For this reason, it may be helpful to combine these different concepts to improve the effectiveness of past proposals. Additionally, further study of the interaction between these concepts could be valuable, especially within the context of a circular economy.

On the one hand, buildings are physical assets that must be investigated through data collection from archives, surveys using various tools, and previous research. On the other hand, buildings may be connected to digital repositories to collect, store, and visualise data in various ways using different technologies. In this context, the term ‘digital inventory’ used in this paper refers to combining the abovementioned concepts.

For better understanding, this section presents a topic analysis, grouping aspects from different domains, as shown in

Table 1. Glossary for keyword selection.

Term	Definition	Domain	Reference
Inventory	“Inventories are ongoing records for identifying, as well as describing heritage places for a range of purposes, including heritage management and protection, and public appreciation”	Heritage Sector	[1]
Digital Building Logbook (DBL)	“It means a common repository for all relevant building data, including data related to energy performance such as energy performance certificates, renovation passports and smart readiness indicators, as well as on the lifecycle GWP and indoor environmental quality, which facilitates informed decision-making and information sharing within the construction sector, among building owners and occupants, financial institutions and public authorities”	Building Performance Sector	[4]
Building Renovation Passports (BRPs)	“A Building Renovation Passport is defined as a document—in electronic or paper format—outlining a long-term (up to 15 or 20 years) step-by-step renovation roadmap for a specific building, resulting from an on-site energy audit fulfilling specific quality criteria and indicators established during the design phase and in dialogue with building owners”	Building Performance Sector	[18]
Material Passports (MPs)	“Materials passports (MP) are (digital) sets of data describing defined characteristics of materials and components in products and systems that give them value for present use, recovery, and reuse”	Circular Economy	[19,20]
Digital Product Passports (DPPs)	“a digital identity card for products, components, and materials, which will store relevant information to support products’ sustainability, promote their circularity and strengthen legal compliance”	EU Regulatory Framework	[21]
Database	“An organized repository of data with functionality for adding, deleting, updating, and retrieving the data”	(Information and Communications Technology) ICT	[22]
Digital Twins (DTs)	“A Digital Twin is a multi-scale representation of a whole consisting of a potential or existing system (physical product, user, and activity) in the real environment, its virtual reflection in the digital space, and the processes of automated exchange of data and information in real-time and using simulation algorithms and historical data or collected from smart sensors to predict the system’s future state or its response to a given situation”	Building Sector—ICT	[23]
Building Information Modelling (BIM)	“set of processes applied to create, manage, derive and communicate information among stakeholders at various levels, using models created by all participants to the building process, at different times and for different purposes, to ensure quality and efficiency”	Building Sector—ICT	[24]
Common Data Environment (CDE)	“agreed source of information for any given project or asset, for collecting, managing and disseminating each information container through a managed process”	BIM Environment	[25]

. The table provides a glossary of the most relevant terms to describe and represent the digital inventory in the built environment from the authors’ perspective, to overcome knowledge fragmentation and integrate approaches from different disciplines. These terms are analysed and compared below to select the most appropriate ones for the query used in the bibliometric analysis developed in Section 4.

The analysis of the concepts briefly presented in Table 1 led to the following observations on conceptual overlaps and differences:

• Some terms may lack meaning without a physical asset to which they are related, while others may refer to environments that are not yet “physical”. For instance, BIM and CDEs are primarily implemented for new projects, which results in different approaches to data collection and storage compared to inventories of existing buildings.
• There is no conceptual overlap between inventories, DBLs, and BRPs, as they serve different purposes. Inventories are widely used in the heritage sector to identify, manage, and protect heritage sites. In the built environment, inventories are potent tools for acquiring knowledge about existing buildings and defining reuse strategies. The Reuse Toolkit, developed as part of the Interreg NWW 739 project, offers guidelines for conducting reclamation audits—activities carried out in buildings scheduled for demolition or dismantling. The result is a “reclamation inventory”, which lists reusable building elements [3]. On the other hand, DBLs are repositories that compile information about buildings, while BRPs combine a DBL with a renovation roadmap that guides the stages needed to make a building zero-emission [26]. BRPs have also been proposed [18] as user-friendly decision-support tools for building owners, particularly useful in refurbishment planning and maintaining an up-to-date view of a building’s lifecycle [27].
• There may be some overlap between inventories, MPs, and DPPs. While MPs are commonly used in the built environment, DPPs are cross-sectoral concepts developed by the EU [28]. However, the specific contents and data structures of DPPs are still not fully defined, though several authors have explored indicative requirements [29,30].
• More broadly, inventories encompass information that also contributes to MPs or DPPs, although their application should be broader, focused on the asset itself. Inventories can be key elements in promoting a deeper understanding and revolutionising the management of the built environment, thus enabling digital circular economy practices. To promote their effectiveness, data standards are crucial to ensure that information is structured consistently and remains valid over time, fostering collaboration among stakeholders with varying interests, backgrounds, and expertise [1].
• Inventories utilise database and repository capabilities to collect information that may not be directly related to ICT. Other technologies that support inventory implementation include Digital Twins (DTs), BIM, and CDEs. These digital tools integrate information from design and construction (BIM/CDEs) and monitoring and management (DTs) phases, adding value to the final digital inventory.
• Overlaps between DTs and BIM arise due to their use of models. However, while BIM typically produces standalone models, DTs require a physical counterpart to remain functional [31].

The progressive mandatory use of Building Information Modelling (BIM) in several European countries has made data-driven processes in the built environment essential. However, the heterogeneity of data from various sources poses significant challenges. The lack of automatic processes using open interfaces makes data exchange tedious, a significant obstacle to implementing circular economy goals in the construction industry [32]. On the other hand, digital technology must face the analysis of the constructed asset, which is paramount to ensure that the actual performance is recorded and reviewed to inform decisions about maintenance, repairs, or replacement. To this aim, the ISO 15686 [33] series focuses on service life planning for buildings and construction. Specifically, part seven addresses the process of collecting, analysing, and giving feedback on service life data from real-world practice, providing guidelines for evaluating the performance of materials, components, and systems used in buildings and constructed assets over time [33]. The goal is to refine and optimise service life predictions and enhance sustainability in the built environment by learning from the actual outcomes. It supports the long-term sustainability of buildings and constructed assets by fostering a dynamic feedback loop that informs better design and maintenance practices. However, the success of its implementation depends on overcoming data collection challenges and ensuring effective collaboration across stakeholders.

To address these challenges, the digital inventory concept can resolve interoperability issues by enabling connections across various systems and thus stakeholders. A similar approach is outlined for the Digital Product Passport (DPP) system from CEN CLC JTC 24 [34], which follows a co-existence model requiring standardisation at the highest level of granularity. In this case, the approach is directed specifically to the digitalization of data and aims to achieve several objectives, including:

• Inclusion of conformant standards;
• Support for technology development;
• Selection opportunities;
• Shorter standardisation timelines.

The DPP system is designed to integrate seamlessly with existing digital systems and platforms, facilitating easy access and sharing of product information among stakeholders.

In this context, the ideal “digital inventory platform” would collect and link data from heterogeneous sources without the need to store all data in one location, as the construction sector inherently deals with heterogeneous data. This concept is further explored in Section 6, where platforms with a similar scope are grouped and analysed. The “platform” concept is flexible and scalable, not tied to a single tool or data collection strategy, and aims to leverage the strengths of each system to efficiently achieve CE objectives.

4. Bibliometric and Scientometric Analysis

The bibliometric analysis aims to develop a quantitative examination of written publications on using inventories for the built environment in a circular design perspective, supported by digital tools, repositories, or similar systems.

As mentioned above, the Scopus database was used to carry out the literature review, considering the time period from 2008 to 2024. To make the research more effective, the search query was defined on the basis of the search tips shared on the Scopus website [35]. For this reason, the proximity operator “Within” (W/n) was used to look for articles containing the words selected in the query in different combinations. Titles, abstracts, and keywords (TITLE-ABS-KEY) of publications were included in the query to have a wide range of publications.

Based on the keywords identified in Section 3, the first query consisted of the following string:

• ((inventor* OR repositor* OR set* OR dataset* OR database OR BIM* OR twin* OR renovation OR environment OR passport) W/3 (data OR digital))

The initial search yielded 971,908 documents, resulting in many publications that were irrelevant to the topic of study. To more accurately capture topics related to the different domains, the final query was refined to include the following search strings:

• To capture topics detailed in Section 3 related to inventories of buildings: (inventor* OR repositor* OR set* OR dataset* OR database OR bim OR twin* OR brp) W/3 (data OR digital);
• To capture topics related to the built environment: (building* OR built OR construction) W/3 (environment OR stock OR building* OR sector OR facility OR domain OR industr*);
• To capture topics related to circular economy/design: (circularity OR circular OR reus* OR re-us* OR passport*) W/3 (design OR economy OR process).

Based on the results from the query above, 154 publications were selected. Data were extracted from the Scopus database and further analysed using statistical and science mapping techniques.

Initially, Microsoft Excel 2016 was used to illustrate the time evolution, geographic distribution, type of publications, and subject area of the selected publications. In a second step, VOSviewer 1.6.20 was used to analyse authors and keywords, cluster bibliometric networks, and visualise data patterns.

Correlations between authors and keywords were analysed using VOSviewer, an open-source software designed for bibliometric mapping of scientific fields. VOSviewer supports the analysis of article similarities through co-authorship patterns, keyword co-occurrence in titles, abstracts, and keywords, and the co-citation of shared references. This tool is particularly useful for visualising relationships within large sets of academic publications [7].

The time evolution of the selected publications is shown in Figure 3. The horizontal axis includes the years of publication, while the vertical one represents the number of publications to show the increase in the number of documents over the years. In the first decade analysed, the number of publications relevant to the identified query did not exceed five yearly. The number of publications began increasing in 2019, with a significant rise in 2023.

The geographical distribution of selected publications (Figure 4) shows that the United Kingdom (21 publications) is the most active contributor, followed by Italy (15 publications), Australia (13 publications), and China and the US (11 publications each). The Netherlands (9 publications) and Germany and Sweden (8 publications each) were also notably active. Overall, Europe produced 80 publications, showing the high relevance of the topic in this area. This trend is also evident in the funding sources, as the European Commission and the Horizon 2020 Framework Programme have financed the highest number of research activities.

The publications are mainly articles (49%) and conference papers (27%). Other types of publication are conference reviews (8%), book chapters (7%), reviews (7%), books (1%), and data papers (1%).

Most publications focus on engineering (25%) or computer science (16%), analysing the potential of digital technologies to enable a circular economy in construction (Figure 5). In environmental science (14%), studies emphasise risk assessment related to environmental sustainability. Many publications referring to social sciences (12%) address the impact of circular economy strategies on the society. Other fields involved are energy (9%), business, management and accounting (6%), earth and planetary sciences (4%), mathematics (3%), materials science (3%), and decision sciences (2%). Arts and humanities are less active than other sectors (2%).

4.1. Authors and Co-Authorship Network

A total of 517 authors published academic documents based on the search criteria specified in Section 4. The co-authorship network, which selected authors with a minimum of two documents, identified 31 authors, with 7 authors having three publications and 24 authors having two publications. Figure 6 shows the density visualisation of the most active authors.

Figure 7 and Figure 8 show two other ways of representing the co-authorship network. Figure 7 shows a network in which authors are divided into clusters, identified by different colours based on the co-authorship relations. The image shows a fragmented situation where each cluster shows a group of strongly connected authors, without connection among groups. This might be related to various topics and approaches developed over the years and in selected geographic areas, as described in Section 4.2. In Figure 8, colours change based on the articles’ publication year, showing that the most recent articles, from 2021 to 2024, have the strongest and most numerous co-authorship relations compared to the papers in the time range 2008–2020.

All figures were developed using the “Co-authorship” analysis from VOSviewer 1.6.20.

4.2. Spatial and Temporal Trends

Based on the data analysed in Section 4.1, which spans diverse geographic regions and publications from 2011 to 2024, a clear temporal and geographic diffusion of digital inventories in the built environment emerges (Figure 9). In Central and Northern Europe, particularly in Austria, Sweden, Switzerland, and the Netherlands, research has been at the forefront of the integration of advanced digital frameworks such as digital twins, BIM-supported resource assessment, and urban-scale material detection [32,36,37,38,39,40,41]. These studies conceptualise digital inventories as static databases and dynamic infrastructures that enable real-time lifecycle assessments, predictive environmental risk modelling, and strategies for circular urbanism. Research on these topics started earlier than in the other geographic areas taken into consideration, which made it possible to consolidate an interdisciplinary approach where digital tools have been tested for several purposes related to the circular economy framing.

In contrast, research from Southern Europe—particularly Spain, Portugal, Italy, and Greece—tends to foreground the operationalisation of material and building passports and digital methodologies for the specific objective of post-disaster material management [26,42,43,44]. Here, digital inventories are situated within frameworks responding to resource scarcity, climate adaptation, and heritage preservation, indicating a regional orientation toward practical and resilience-focused applications of circularity principles. Such topics have acquired more importance in the last few years (2023–2024), which might be due to the increasing impact of climate change in these regions, where emergencies like floods and droughts are more frequent every year.

In Asia, specifically in China, the thematic focus diverges, centring predominantly on industrial-scale data retrieval and management systems [45,46]. While these studies advance the computational infrastructure necessary for handling large datasets in construction, they engage less directly with the conceptual frameworks of circular economy or sustainability that dominate European discourse.

Meanwhile, recent research (2023–2024) in Australia reflects a targeted interest in material stock and flow analysis for residential housing. This research highlights the unique challenges of decentralised urban forms in Australia and offers methodological innovations for material tracking at the urban scale [13,47,48,49]. To conclude, research from Africa, particularly South Africa and Nigeria, focuses on bibliometric analyses and mapping circular economy business models within the construction sector [50,51] and dates back to 2024. This reflects an initial stage of embedding digital inventories within broader socio-economic transformations, emphasising the theoretical groundwork necessary for technological uptake.

Analysing these trends is analytically significant as it highlights the practical implications of adopting digital frameworks, such as digital twins, material passports, and inventory platforms. These tools are not just theoretical concepts, but have the potential to facilitate cross-border collaboration, standardisation, and innovation in sustainable building practices. The non-homogeneous adoption of such concepts in the different geographic areas, with implications for both theory and practice, demonstrates that digital inventories are not neutral technologies but are deeply influenced by regional socio-economic conditions, policy landscapes, and technological infrastructures. Recognising these differences is crucial for developing globally relevant yet locally adaptable frameworks for digital inventory management in the construction industry’s transition towards a circular economy.

4.3. Co-Occurrence Network of Keywords

To analyse the co-occurrence of keywords, the authors used the ‘keywords’ function in VOSviewer 1.6.20. In this visualisation, the size of each keyword reflects its occurrence, while colours represent clusters, and the proximity between keywords indicates their similarity. The first network was created using only index keywords. Of the 1175 keywords, 39 met the threshold of a minimum occurrence of 5. This resulted in five clusters based on the recurrent keywords (Figure 10). However, the authors found that these clusters did not align well with the research scope, as the connections between keywords seemed less relevant.

Therefore, a second network was generated, this time including both author and index keywords. With a total of 1475 keywords, 52 met the occurrence threshold of five or more (Figure 11). The second network provided a clearer and more logical representation, with more related keywords. Four research clusters were identified: (i) circular economy; (ii) architectural design/construction industry; (iii) digital twin; and (iv) sustainable development. These clusters are strongly interconnected, with numerous links between keywords across different clusters. The key findings of each cluster are discussed in detail in Section 5.

5. Topic Analysis

The scientometric analysis of the literature identified four main groups related to the use of inventories in the reuse processes of building elements, supported by digital tools and repositories:

• Cluster 1: Inventories and Circular Economy;
• Cluster 2: Inventories and Architectural Design/Construction Industry;
• Cluster 3: Inventories and Digital Twins;
• Cluster 4: Inventories and Sustainable Development.

The following section offers an overview of each cluster, highlighting key concepts from the literature to outline the current state of research in each area. Each topic is analysed by addressing the following questions:

• What techniques are being used?
• Are these techniques specific to certain processes, or are they commonly within the construction sector?
• Are these techniques widely applied in the built environment?
• What is the primary focus of their application?
• What are the key findings?
• What challenges are associated with using inventories in circular economy initiatives?

5.1. Cluster 1: Inventories and Circular Economy

The circular economy is a sustainable model that aims to reduce waste and extend the life cycle of products by promoting strategies such as reuse, recycling, and minimising waste and pollution. Within this framework, the circular approach should keep materials circulating for as long as possible, minimising the need for new resources. Doing so helps mitigate environmental impacts such as pollution and carbon emissions.

To achieve this, the use of inventories tracking materials and products available for reuse would be highly beneficial. Inventories may help to identify reusable components, facilitate efficient processes, and track resources effectively reused. Furthermore, inventories that collect and organise data in a structured manner are well-suited for developing applications based on Machine Learning (ML) or Artificial Intelligence (AI). For this reason, over the years, numerous efforts have focused on implementing circular economy principles using data across various stages of the construction sector. Some examples include:

• Developing optimal strategies to predict demolition waste generation [52] or minimising waste through deconstruction [53];
• Predicting the presence of hazardous materials in buildings using ML [37,54];
• Enabling buildings materials reuse using urban mining methods based on ML [55];
• Creating a comprehensive resource cadastre for existing buildings and assess circularity needs at the urban scale using street view imagery and computer vision [56];
• Developing optimal deconstruction or disassembly methods based on digital technologies [57,58,59]);
• Exploiting existing databases to explore the potential of the building stock as material bank [60].

Among the various stages in the CE processes, the demolition phase is often overlooked, yet it holds significant potential for material recovery. Furthermore, data collection for this phase remains relatively unexplored, leading to a gap in storing critical information on disassembly and demolition techniques—insights that are essential for achieving circular economy objectives.

To address this gap, Ivanica et al. (2022) developed a Life Cycle Inventory (LCI) specifically for building demolition, applying a replicable methodology intended for future Life Cycle Assessment (LCA) studies [61]. The research is based on data collected from a number of buildings in Germany. The case studies were split into their elements during the demolition phase to enable the development of a database useful for generating case-specific data components and producing construction-specific inventory data. The study used the collected information to create a Microsoft Excel based LCI database, enabling the modelling of partial demolition or maintenance activities based on benchmarks from the case studies. The methodology requires minimal data input, making it applicable during the early design stage of a building.

Although the approach is promising, the database includes only a small sample of residential buildings, limiting its application to structures with similar characteristics and context. For this reason, an extension of the database is required to include a broader range of building types and methods. This methodology could similarly be applied to other phases of the process, enabling the development of a versatile database that serves as a decision-support tool.

Another notable initiative is the Circularity Dataset Standardisation Initiative, launched in 2018 by the Ministry of the Economy of Luxembourg [28]. Its aim is to develop a global open-source industry standard that facilitates the exchange of circularity data among stakeholders. To improve the efficiency and transparency of data exchange, the Product Circularity Data Sheet (PCDS) framework was developed. The main components of PCDS include a template for standardised circular data, a completion guide, and a generalised draft of the data sheet’s IT infrastructure [62].

Highlighting the relevance of this initiative, the International Organization for Standardisation (ISO) is in the process of developing a related standard, designated as ISO 59040, which focuses on circular economy principles and the Product Circularity Data Sheet framework [63].

Therefore, the use of inventories in CE is crucial for fostering communication and cooperation among supply chain actors and, for instance, reducing the amount of waste generated. The study by Güngör and Leindecker (2024) reviews current inventory and supply chain tools, investigating their most interesting functions [44]. Their findings suggest that future research should explore the use of web-based technologies in construction supply chain (CSC) management to enhance efficiency, transparency, and real-time communication among stakeholders.

Within this context, Yu et al., 2023 [64], designed a web-based artefact of a Construction Information Platform (CIP), which was then validated against a series of Reference Architecture (RA) models to bridge the gap between technical and business stakeholders. RA models serve as a comprehensive communication tool involving multi-disciplinary views [64].

By examining these technologies and related concepts, researchers can uncover methods to streamline processes, lower costs, and enhance collaboration across various supply chain stages within a circular economy framework. Circular economy platforms such as Cirdax, Concular, and Upcyclea are rapidly gaining traction as key enablers of sustainable practices, offering digital solutions that facilitate material reuse, waste reduction, and lifecycle tracking in various industries, particularly construction and manufacturing [28,65,66]. Such platforms represent key areas for further exploration for inventory tracking, digital collaboration tools for project management, and data analytics systems for demand forecasting and logistics management.

As the construction industry continues to embrace digitalization and sustainability, inventories will play an increasingly essential role in fostering innovation, improving data-driven decision-making, and enabling the transition to circular economy practices.

5.2. Cluster 2: Inventories and Architectural Design/Construction Industry

Inventories provide a structured record of materials, components, and resources that are available for reuse or recycling [67]. As the industry shifts towards sustainable practices, particularly within a circular economy framework, inventories enable architects and builders to make informed design choices prioritising resource efficiency and waste reduction. By cataloguing reusable materials and tracking their lifecycles, inventories enable the development of reuse-driven designs incorporating reclaimed building components. By cataloguing reusable materials and tracking their lifecycles [33], inventories enable the development of reuse-driven designs incorporating reclaimed building components. This contributes not only to environmental but also to economic sustainability, because having access to an organised inventory of available materials minimises procurement expenses and streamlines supply chain management. For this reason, the use of inventories is increasingly relevant for supporting sustainable construction practices and fostering a circular approach to architectural design. However, the integration of such inventories faces challenges, including data standardisation and the adaptation of tools for existing built environments.

Within this framework, the use of BIM and other digital tools for data collection and storage has been extensively analysed in the literature. Common applications include:

• The use of BIM and 3D scanning techniques for data capturing [36,68,69];
• BIM data model requirements for asset monitoring [70] and lifecycle management [71];
• Integration of digital documentation in BIM for reuse and retrofit interventions [72,73,74,75];
• Integration of BIM and LCA [76,77,78,79,80];
• Material passports implementation in a BIM environment [81,82,83].

Dervishaj and Gudmundsson (2024) analysed existing digital tools that could aid designers and other professionals in the construction industry in promoting circular economy practices [39]. Key findings in their research reveal limitations in the functionalities offered by the tools, highlighting the need for further development and focusing on a more comprehensive approach. Even though BIM is a valuable tool for creating building inventories, its application faces challenges due to data gaps and standardisation difficulties in the built environment sector. While BIM is widely used in new construction, partly due to its growing regulatory requirement in several European countries, processes in the built environment should ideally be data-driven.

Building inventories can support designers and architects in making data-driven decisions that optimise both new and existing structures. Inventories may contribute to optimal design on different aspects:

• Enhanced decision-making [84,85]: by providing accurate data on building components, inventories enable design professionals to make well-informed decisions. Thus, designers may identify areas for improvement earlier in the process, suggesting potential upgrades before any damage occurs.
• Energy efficiency and sustainability [86,87]: with data collected for building inventories, designers can identify opportunities for energy-saving measures, such as improved insulation, HVAC upgrades, or renewable energy integration. Optimising these elements might help reduce the well-known “Performance Gap” issue [88].
• Retrofitting and renovation [89,90,91]: when dealing with existing structures, inventories reveal hidden details like structural constraints, material degradation, or previously installed systems. This information supports designers in planning feasible retrofits and renovations that meet modern standards without compromising the building’s structural integrity.
• Cost control [92]: inventories enable designers to know exactly what a building needs. This helps them streamline costs, avoid unnecessary expenses, and allocate resources efficiently.
• Improved collaboration and communication [81]: design teams can communicate more effectively with stakeholders when data are organised efficiently. A shared, data-driven inventory enhances transparency and helps keep everyone aligned, reducing misunderstandings and delays.
• Compliance with codes and standards [93]: detailed building data ensures that new designs and renovations are compliant with local codes, safety regulations and environmental standards. Inventories make it easier to validate designs with regulatory requirements, avoiding compliance issues and ensuring buildings are up to code.

Building inventories may support architectural design by ensuring data-backed, sustainable, and compliant building solutions. However, the fragmented landscape of the construction industry makes the creation of inventories complex due to the lack of processes for data conservation from the design stage to the construction one.

5.3. Cluster 3: Inventories and Digital Twins

Digital twins (DTs), as discussed in Section 3, may support the implementation and updating of building inventories by offering powerful, data-driven insights into building performance and lifecycle management. By integrating real-time with historical data, digital twins can deliver predictive insights, facilitate maintenance, and optimise building operations.

On the other hand, inventories functioning as comprehensive databases support activities ranging from initial design to maintenance, renovation, and reuse. Their integration with digital twins is promising, as they might empower stakeholders to make proactive, data-driven decisions, enhancing asset management, sustainability, and resilience throughout the building lifecycle. As these technologies evolve, they aim to create a more connected built environment that meets the dynamic needs of stakeholders.

Previous research on these themes has largely explored digital twins (DTs) for their data-tracking and registration capabilities. However, this work appears to remain mostly at the research level, with limited implementation in industry, where DTs are often seen as the next evolution of BIM. Current applications include the following:

• Enhanced BIM [75]: DTs extend Building Information Modelling (BIM) capabilities, enabling designers and planners to simulate and visualise the project lifecycle in real-time. This helps identify design flaws and optimise building performance early in the planning phase.
• Scenario testing [94]: DTs enable the testing of various scenarios, such as structural loads, energy consumption, and emergency response-helping stakeholders make better, informed decisions before construction begins.
• Progress tracking [40]: DTs can track real-time construction progress by syncing physical changes on-site with digital models. This is particularly useful for identifying discrepancies between estimated and actual construction, improving accuracy and efficiency.
• Resource and site management [73]: By integrating DTs with IoT devices, such as sensors and GPS, site managers can monitor resources, track equipment, and optimise logistics, reducing waste and ensuring safety.
• Facilities management [95]: After construction, DTs act as “living” models for facilities management, providing detailed, real-time insights into the building’s systems (e.g., HVAC, electrical, and plumbing). This enables predictive maintenance by detecting issues early.
• Energy optimisation [96]: DTs monitor energy consumption in real-time and suggest adjustments to improve efficiency, reducing operating costs and environmental impact throughout the building’s lifecycle.
• Long-term asset monitoring [97]: DTs allow owners to track an asset’s performance and condition over time, helping them plan maintenance, renovations, or replacements based on data-driven predictions, thus extending the asset’s useful life.

DTs represent a good solution for creating and maintaining up-to-date inventories of buildings. By integrating building data with real-time updates, DTs provide a dynamic and precise record of all assets within a building [98]. The following outlines their contributions to inventory development:

• Asset tracking: DTs track physical assets such as furniture, machinery, equipment, and building components (e.g., HVAC systems, electrical panels, and plumbing fixtures). Each item can be assigned a unique identifier and stored within the DT, allowing facility managers to know the exact location, status, and specifications of every asset in real-time. This way, a close correspondence between the entity and the data obtained is ensured [99].
• Material and component inventory: DTs can include detailed data on materials used in construction (e.g., type, quantity, and quality of materials like steel, concrete, glass), tracking and monitoring the real conditions of the construction site [100]. This information helps create a detailed inventory of structural components and assists in maintenance, renovations, or even recycling and repurposing materials in the future.
• Condition and maintenance records: By linking IoT sensors with the DT, the system can monitor the condition of assets and provide historical maintenance records [101], helping managers track wear and tear, manage warranties, and schedule predictive maintenance to extend asset lifespans.
• Space management: DTs can keep track of spaces within a building, such as office rooms, meeting rooms, storage areas, and utility spaces [102]. With real-time occupancy and usage data, DTs enable more efficient space planning and utilisation.
• Real-time updating: DTs can automatically update themselves in response to changes [103] (e.g., when new equipment is installed, items are moved, or areas are assigned a new function). This ensures that the inventory remains accurate and current, without issues related to manual updates.

While these applications show the benefits of DTs, aspects such as high costs, data complexity, and the need for highly technical expertise often limit implementation [98]. Nevertheless, as costs decrease and expertise becomes more widespread, the construction industry will be likely to adopt DTs at a faster pace, fostering more automated, data-driven, and sustainable construction workflows.

5.4. Cluster 4: Inventories and Sustainable Development

Sustainable development in the built environment seeks to create buildings and infrastructure that meet current needs while preserving resources for future generations. Within this paragraph, the authors refer to sustainable development, focusing on its environmental aspect, while social and economic aspects are considered out of scope in this specific study. Within this context, the production of inventories plays a crucial role, acting as detailed databases that contain information on building materials, systems, energy use, and spatial layout.

Accurate inventories help identify areas for improvement, whether through energy retrofits, sustainable material choices, or more innovative operational strategies [48,91,104]. Furthermore, building inventories facilitate compliance with green building standards and certifications by providing comprehensive documentation of a building’s performance and environmental impact [105,106]. As sustainable development becomes a global priority, building inventories is essential for creating resilient, efficient, sustainable buildings that contribute to a healthier and more sustainable future [107].

More specifically, building inventories play a critical role in fostering sustainable development by providing a robust foundation for informed decision-making across the building lifecycle [57,108,109]. The following are some of the sustainable development aspects that may benefit from the use of inventories:

• Resource efficiency and material management [110]: building inventories collect and store data on material quantities, properties, and recyclability, showing building components’ composition and state. Furthermore, inventories facilitate the integration of end-of-life considerations into renovation strategies or reuse-driven design. This approach reduces environmental impact but also promotes sustainable resource management, ensuring that materials are discarded as waste only when there is no other option.
• Energy optimisation [26]: building inventories also catalogue system specifications, such as HVAC systems, lighting, and others, which help identify inefficiencies in energy use. For example, accurate information on the building systems may aid retrofitting and upgrades to reduce energy consumption and greenhouse gas emissions. When paired with digital twins, inventories enable real-time monitoring and predictive analytics to optimise energy performance dynamically.
• Lifecycle sustainability assessments [41]: building inventories allow for comprehensive LCAs by providing accurate data about building’s components and systems. LCAs inform sustainable design decisions by evaluating the environmental impacts of material extraction, manufacturing, transportation, usage, and disposal. This encourages the use of low-impact materials and sustainable construction practices.
• Improved maintenance and longevity [48]: detailed records of a building’s structural and system components facilitate proactive maintenance, extending the lifespan of components in both new and existing assets. Early detection and resolution of issues reduce the need for resource-intensive repairs or replacements, lowering the overall environmental footprint.
• Facilitating green certification and compliance [111]: The inventories’ capacity to provide necessary documentation on materials, energy systems, and operational data may facilitate compliance with green building standards. Indeed, inventories support audits and assessments needed for certifications, ensuring that sustainability benchmarks are met and kept through the building lifecycle.
• Urban sustainability and smart cities [112]: when aggregated at a community or city level, building inventories contribute to broader urban planning efforts, promoting sustainable land use and infrastructure development. Inventories feed into smart city initiatives, enabling data-driven strategies to reduce environmental impact while enhancing the quality of urban living.
• Resilience and climate adaptation [97]: by cataloguing an asset’s vulnerability to climate risks, inventories may help design adaptive measures to mitigate risks, ensuring infrastructures are resilient to extreme weather, flooding, or temperature fluctuations.

When effectively utilised, building inventories are potent tools for advancing sustainability in constructing and operating the built environment. The integration between detailed datasets on building composition and advanced technologies may help stakeholders meaningfully contribute to global sustainable development efforts.

6. Platforms for Circular Economy

As discussed in Section 5.1, web-based platforms can significantly enhance decision-making and resource allocation in the construction industry, fostering more sustainable, circular, and resilient supply chain practices [110]. Building on the results of the bibliometric and topic analysis, this section introduces and compares some of the existing ICT systems for the circular economy that might be helpful in defining the technology of the digital inventory for reuse. The authors carefully selected platforms deemed significant for this type of analysis, encompassing both well-established platforms characterised by their extensive technological evolution and maturity and promising emerging platforms. Their selection was also influenced by the platforms’ relevance across various geographic regions, ensuring a comprehensive representation of diverse contexts and innovations.

The analysis focuses on showing different approaches and strategies; by examining these platforms, the authors aim to highlight how various organisations and initiatives address challenges within the CE framework. The analysis offers insights into best practices and innovative methodologies for defining inventories of the built environment to facilitate the effective reuse of building components. For each platform identified, qualitative and quantitative analyses were carried out. For the qualitative analysis the following criteria have been analysed: primary focus, key tools, technological integration, presence of a marketplace, target users, strengths, weaknesses, and geographic area (

Table 2. Qualitative analysis and comparison of selected platforms.

Features	Platforms
	Cirdax	Concular	Upcyclea	Re-Sign	CB’23	Madaster	CCBuild	Palats
Primary focus	Digital inventory, lifecycle tracking, and blockchain-backed ownership for construction materials	Facilitating reuse by matching reclaimed materials from demolitions to new construction projects	Circular economy solutions for the entire building lifecycle, including design for disassembly	Promoting creative and collaborative upcycling of construction materials	Frameworks and guidelines to standardise circular construction practices and tenderings in the Netherlands	Registration and documentation of building materials	Circular construction tools and marketplace for Sweden	Internal reuse of office furniture and assets
Key tools	Blockchain, 3D scanning, materials passports, inventory app, BIM tool, CO2 calculator	LCA software, Building Resource Pass, BIM tool	Inventory app with AI features, BIM tool, Circular passports	Collaborative tools for design and reuse, digital hub for professionals	Frameworks, material passports, guidelines, and protocols	Circularity insights, material passports, digital building twins, and circularity indices	Marketplace, inventory app, product bank	Inventory app, QR codes, sustainability insights
Technological integration	Blockchain, reversible BIM tools	AI, image recognition for materials identification	Digital material passports, lifecycle tracking	Collaboration platforms for design	Standardised digital tools	BIM integration, cloud-based registration platform	Digital inventory, marketplace	QR codes for tracking, mobile inventory management
Reuse marketplace	Yes, supports sourcing of reusable materials	Yes, connects demolition sites with new construction projects	Indirect; focuses on lifecycle-based reuse strategies	Promotes creative upcycling sharing	No; focuses on guidelines and frameworks	No; focuses on registration, documentation, and transparency	Yes, marketplace for reusable building components	Yes, internal to the organisation
Target users	Construction firms, real estate developers	Architects, developers, demolition companies	Building owners, designers, developers	Architects, designers, construction firms	Policymakers, contractors, developers	Real estate owners, facility managers, developers	Contractors, developers, facility managers	Corporate real estate managers
Strengths	Advanced technology; traceability and transparency	AI-driven efficiency; market connectivity	Lifecycle focus; comprehensive circular passports	Creative reuse; collaborative design	Structured frameworks; industry-wide impact	Comprehensive documentation; global reach	Collaborative platform; marketplace functionality	User-friendly; focused scope
Weaknesses	Complexity; limited adoption	Geographic limitation; data dependency	Lacks marketplace; complex for small projects	Limited scalability; manual processes	Theoretical focus; region-specific	Passive platform; data management burden	Limited to Sweden; development stage	Narrow application; manual processes
Geographic area	The Netherlands, Europe	Germany, expanding to Europe	France, expanding to Europe	Italy	The Netherlands	The Netherlands, Europe	Sweden	Sweden
Reference	[113]	[28,113]	[113]	[114]	[28]	[28]	[115]	[116]

).

A quantitative analysis was performed based on the information collected and analysed in Table 2. Each platform was assigned a score for four criteria defined by the authors:

• Technological maturity;
• Data integration capabilities;
• Industry adoption;
• Scalability.

The authors assigned the scores for such criteria on a scale from one to five, where one represents the lower level and five is the highest score (

Table 3. Quantitative analysis for selected criteria.

Criteria	Platforms
	Cirdax	Concular	Upcyclea	Re-Sign	CB’23	Madaster	CCBuild	Palats
Technological maturity	2	4	3	1	3	5	4	3
Data integration capabilities	3	4	3	1	3	4	3	2
Industry adoption	2	4	3	1	4	5	4	3
Scalability	3	3	3	2	4	5	4	3

).

All platforms present strategies to improve circular construction and sustainability but differ in approach, functionalities, and scope. Based on the points given to the technological maturity criterion, the selected platforms can be categorised as follows:

• Technologically mature platforms (well-established, feature-rich, scalable, and with demonstrated industry use): Madaster, CCBuild, Concular;
• Mid-Maturity Platforms (functionally solid, growing adoption, limited in scope or regional focus, but scalable): Upcyclea, CB’23, Palats;
• Emerging/niche platforms (more recent platforms, region-specific, or still scaling up in features or target users): Re-sign, Cirdax.

Not all platforms include marketplaces for selling and purchasing products. While Concular and CCBuild offer strong marketplace features for reclaimed materials, Upcyclea, CB’23 and Madaster focus more on lifecycle documentation than active trading.

CIRDAX, Concular, and Madaster are notable for using advanced technologies. However, these can pose challenges for adoption due to complexity and cost. CIRDAX employs blockchain and 3D scanning for precise traceability and aims to reduce the risk of material loss or damage by providing ownership tracking [117]. However, such an advanced technology can be challenging for non-technical users, making adoption harder compared to more user-friendly oriented platforms like PALATS or Re-sign, which have simpler workflows. Moreover, its recent release as a new platform leads to limited adoption since it lacks the market reach of other platforms such as Madaster or Concular. However it is promising in terms of scalability. Concular uses AI-driven solutions for matching reclaimed materials to new projects [118]. The effectiveness of AI strategies relies on high-quality data inputs, which might be an issue when information is incomplete or inconsistent. Furthermore, it is primarily focused on the market in Germany, restricting broader international adoption when compared to global platforms like Madaster. On the other hand, Madaster focuses on integrating a material passport framework within the BIM environment, offering a robust system for material registration and transparency [119]. It has a strong presence in Europe, particularly in the Netherlands, Belgium, and the UK. Thus, it is more widely adopted than platforms like CCBuild or Concular, which target specific countries/regions. However, the need to collect and use detailed documentation may lead to an unbearable effort for smaller firms.

For the abovementioned reasons, these platforms may represent a challenge in complexity, data dependency, and high implementation costs, making them much less accessible for smaller firms or non-technical users.

In contrast, Upcyclea emphasises lifecycle management and designing buildings for future disassembly, promoting long-term circularity and managing materials throughout their lifecycle employing comprehensive circular passports [120]. While Upcyclea is comprehensive in its lifecycle approach, it lacks the marketplace functionalities from Concular or CCBuild. Furthermore, lifecycle tracking and circular passports might limit its application in smaller firms or simpler projects. Also, Re-sign promotes long-term sustainability fostering collaborative design, through a digital hub where professionals can promote their own skills, but it sets itself apart with a creative and collaborative focus on artistic upcycling, involving designers and architects in unique reuse projects [114]. However, such a creative approach limits scalability and industry adoption, as solutions are often project-specific and difficult to standardise, unlike the standardised processes of CB’23. CB’23 provides clear guidelines and protocols for circular construction, particularly for the Dutch market. It is effective for influencing large-scale adoption of circular practices, but does not offer practical tools or marketplaces for immediate reuse [121]. This makes it less hands-on compared to platforms like Concular or CCBuild, which facilitate material exchanges.

CCBuild and Palats are both dedicated to the Swedish context, restricting their international reach. CCBuild provides a suite of digital tools, including an inventory app and a product bank, to facilitate the documentation and management of reusable building materials. These tools support internal and external reuse processes, encouraging stakeholder cooperation for material reuse [115]. The IVL Swedish Environmental Research Institute operates CCBuild with other partners. It is well-established in Sweden and collaborates with various industry players. On the other hand, Palats stands out for its user-friendly design and internal asset management, specifically for office environments. Unlike the broader scope of platforms such as Upcyclea or Madaster, Palats focuses narrowly on tracking office furniture and organisational assets [116], making it highly specialised but limited in application for large-scale inventory management.

In summary, while CIRDAX, Concular, and Madaster excel with technology-driven solutions, they risk complexity and higher barriers to adoption. Upcyclea and CB’23 offer lifecycle management and standardised frameworks but lack immediate reuse tools. Re-sign and Palats focus on niche areas—creative upcycling and internal asset tracking, respectively—limiting their scalability. CCBuild and Concular bridge practical reuse through marketplaces, though their effectiveness is constrained by regional availability. Each platform contributes uniquely to circular construction, serving different needs within the industry.

This section includes several significant initiatives in the European context, however it does not encompass every initiative in the field. By presenting a selection of noteworthy examples, the list serves as a foundational resource for understanding the landscape of current efforts. Readers should view it as a starting point for further exploration rather than a comprehensive analysis, recognising that numerous other initiatives may exist beyond those listed.

The analysis revealed an increasing demand for systems that are able to integrate CE collaborations holistically, fostering a co-existence approach as promoted by the European Committee for Standardisation (CEN) in the EN CLC JTC 24. The co-existence in the context of digital transformation refers to the parallel functioning of the old and new systems, allowing a seamless transition from legacy to target systems [34]. This approach minimises the impact on business operations and customer experience during the digital transformation.

7. Discussion

This paper explores the concept of digital inventories from a circular economy perspective, analysing current solutions in the built environment and proposing new approaches for integrating diverse sectors. Various terms have been considered and compared to analyse conceptual overlaps and differences (Section 3). In line with the work of [3], our study confirms that efficient inventories are key elements in reusing building products.

The comparative analysis of previous studies highlights several pros for applying digital inventories in the broad circular economy context. A key element involves continuously checking, updating, and monitoring material flows within the circular process, ensuring that information remains traceable and accessible. A starting point for exploring the potential of building stock as a material bank is leveraging existing databases [60,61], together with the creation of new frameworks such as the Product Circularity Data Sheet [62]. Using inventories in the CE context is also helpful for communication strategies to foster collaboration among stakeholders and reduce waste generation [26]. In this context, key areas for exploration include web-based platforms for inventory tracking, digital collaboration tools for managing projects, and data analytics systems for demand forecasting and logistics management.

Building on this, another important advantage is the integration of inventories with innovative technologies currently used in the construction industry, such as BIM, ML, and 3D scanning, in order to develop standard processes for data collection, storage, and use [39,82] to promote circular economy practices. However, the current approach reveals limitations in implementing such integration in the practice. For instance, BIM and DTs are valuable tools for creating building inventories; however, their application in the existing built environment faces challenges due to data gaps and standardisation difficulties.

Inventories offer several advantages for optimal design, enabling data-driven decisions and fostering enhanced decision-making, cost-effectiveness, and improved collaboration and communication [84,87,91,93].

More specifically, inventories serving as comprehensive databases are necessary to develop digital twins to create a more connected built environment. Previous research on these themes has largely explored DTs for their data-tracking and registration capabilities [40,73,97]. However, this work remains mostly at the research level, with limited implementation in industry, where DTs are often seen as the next evolution of BIM [75].

Accurate inventories contribute to fostering sustainable development by helping identify areas for improvement through energy retrofits or sustainable materials choices and facilitating regulatory compliance with green building standards by providing comprehensive documentation of a building’s performance and its environmental impact [26,110].

Despite several promising solutions, the digital inventory tool landscape remains highly fragmented, with significant challenges to address [28]. These challenges include integration across platforms, standardisation of data formats, and ensuring accessibility and ease of use for all stakeholders involved in the construction process [67]. Furthermore, a system based on the co-existence approach, framed within the broader context of digital transformation, is currently not implemented despite strong recommendations from the European Commission [34].

While this study provides valuable insights into the potential of digital inventories to support circular economy strategies, several limitations should be acknowledged. First, the bibliometric and scientometric analysis is based on selecting keywords the authors considered relevant for defining the digital inventory concept. This may influence the selection of papers based on the query described in Section 4. Furthermore, while the authors’ approach to selecting platforms offers a broad and pertinent perspective in Section 6, it does have notable limitations. Firstly, focusing on both mature and emerging platforms may lead to an unequal comparison, as the former typically benefit from years of refinement and user feedback, while the latter may still be in developmental stages and not fully representative of their potential. Finally, the emphasis on technological maturity might lead to neglect of cutting-edge innovations that are still in their infancy but could disrupt traditional models in the future. Overall, while the strategy aims for inclusivity and relevance, these limitations suggest the need for a more nuanced evaluation that accounts for a wider array of platforms and their unique contexts.

Given these considerations, future applications of digital inventories in circular construction practices depend on developing a more flexible system, which may be referred to as a Digital Inventory Platform (DIP). A DIP would collect and link data from heterogeneous sources without the ambition of storing all data in a single location, as heterogeneity is inherent to the construction sector. This platform would function as an integrated system designed to gather, organise, and interconnect from various disparate sources commonly found in the construction sector. Rather than attempting to consolidate all data into a centralised repository, which may not be feasible due to differences in data formats, structures, and origins, the platform would focus on linking and harmonising data while preserving its distributed nature. This approach acknowledges the inherent heterogeneity of the construction industry, where data are often fragmented across multiple systems, tools, and stakeholders, and emphasises interoperability over uniformity. By enabling seamless data integration and access, such a platform would support collaborative decision-making, enhance transparency, and improve efficiency without imposing rigid data management constraints.

8. Conclusions

This study explored the role of digital inventories as a possible solution for the built environment, combining different aspects to facilitate the transition towards a circular economy. This study’s originality lies in combining concepts related to the construction industry’s digital transformation, such as DTs, and existing cataloguing methods for constructed assets, such as inventories. This study contributes to the research by defining, analysing, and proposing digital inventories as a valuable strategy for implementing the circular design in the built environment. The findings demonstrate that these systems are instrumental to (i) facilitate the implementation of circular design in the construction industry; (ii) serve as support-decision tools within the architectural design environment, (iii) integrate existing technologies such as digital twins, and more traditional ways of collection information on constructed assets; and (iv) foster sustainable development by identifying areas for improvement, through energy optimisation, using more sustainable materials and implementing smarter choices.

However, despite the identified key benefits, challenges regarding data standardisation, interoperability, and data management must be addressed to unlock these systems’ potential fully.

Future trends should emphasise the importance of addressing data heterogeneity in the construction industry by adopting more comprehensive strategies for inventorying buildings and assets and developing robust frameworks for data integration. Furthermore, future research should focus on assessing these systems’ economic and social impacts in practice and exploring policy mechanisms to support their widespread adoption.