Design and development of blockchain-enabled information management system for building integrated photovoltaic projects Open Access

BIPV is an effective method of onsite solar energy generation while performing the numerous tasks of a building envelope, such as providing privacy, shelter, protection and insulation (Martin-Chivelet et al., 2022). It consists of PV modules integrated into building envelope elements such as facades, roofs, walls, windows, skylights, balconies and pergolas (Gholami et al., 2021; Yang et al., 2019). According to the International Energy Agency (IEA) Photovoltaics Power Systems (PVPS) programme (task 15), a BIPV module is defined as:

Compared with rooftop solar, BIPV uptake is very low; however, it is rapidly developing with technical advancements and the reduction of module costs (Yang et al., 2019). BIPV applications are now receiving satisfactory stakeholder attention due to their unique characteristics and the ability to achieve sustainability goals (Osseweijer et al., 2018). For BIPV, the main requirement is to increase the efficiency of design and management to deliver the best value for money solutions (Wijeratne et al., 2019). The key reasons preventing effective BIPV design and management are (1) the lack of understanding and collaboration across stakeholder sectors (Curtius, 2018) and (2) ineffective information communication (Gholami et al., 2019). New products often reach the BIPV market; however, they are not well promoted among clients and design stakeholders (D'Amnrosio et al., 2021). BIPV products are mostly imported; therefore, the compatibility between the standards of the two countries should be well-assessed (Ballif et al., 2018). Fire and electrical safety information, including testing outcomes and compliance certificates, is crucial for BIPV design, installation and maintenance (Yang et al., 2021). BIPV projects have detailed documentation that are vital to buildings' operations and maintenance (O&M) (Ning et al., 2018). However, effective stakeholder collaboration and flawless information management are rarely seen in the BIPV industry (Wijeratne et al., 2019). Therefore, the adoption of BIPV in building construction has not yet reached the required standards or achieved stakeholder acceptance.

Blockchain is a promising information communication technology (ICT) which enables decentralised information sharing and management with a high level of transparency, security and accountability (Elghaish et al., 2022). According to Seebacher and Schüritz (2017), blockchain can be defined as follows:

It has many characteristics such as immutability, provenance, decentralised control and no information gaps, which make it suitable for dealing in a trustless environment (Khalid et al., 2020). Blockchain technology can provide open/restricted access to project information depending on how access should be given to the stakeholders (Das et al., 2022). It has several unique features, such as distributed ledger technology (DLT) and smart contracts to ensure secure information sharing and communication without the involvement of an administrative body (Lee et al., 2021).

Blockchain has been identified as an effective technology for diverse applications in the construction sector (Yang et al., 2020a). It has the ability to simplify the complex nature of construction projects via decentralisation, digitalisation and integration. The current areas of blockchain application in construction industry include (1) project information management (Das et al., 2022), (2) supply chain and logistics management (Liu et al., 2021), (3) construction process management (Mahmudnia et al., 2022), (4) equipment leasing (Jiang et al., 2021), (5) prefabricated building elements manufacturing (Wu et al., 2022), (6) asset management (Perera et al., 2020), (7) contract management (Li and Kassem, 2021), (8) quality assurance and inspection (Wu et al., 2022), (9) facilities management (Hijazi et al., 2022) and (10) ownership protection of intellectual property (Das et al., 2022). Blockchain can deliver three main types of services under the above areas: (1) information sharing and management, (2) stakeholder collaboration and (3) facilitation of trades (Das et al., 2022; Mohammed et al., 2021).

Blockchain technology holds the suitable characteristics to offer effective digital assistance to BIPV projects (Zhang et al., 2022). Nevertheless, it is vital to understand (1) the techniques blockchain uses to solve BIPV-related issues, (2) how these techniques address the BIPV issues and (3) whether the issues are fully or partially addressed by blockchain technology. Additionally, it is vital to understand why blockchain technology is a better solution for BIPV information management. A clear research gap can be seen in exploring the above aspects. In fact, there is little discussion about blockchain adoption for stakeholder collaboration and information management in BIPV projects. Therefore, this study intends to fill the above research gap by exploring how blockchain can be adopted to improve BIPV projects management. The aim of this study is to explore how blockchain technology can assist in supply chain integration and information management in BIPV projects to avoid current issues and limitations. The main objectives are (1) to understand how blockchain technology can be applied in BIPV projects, (2) to develop a blockchain platform to demonstrate its functions and how it can address current BIPV issues and limitations and (3) to validate the developed blockchain platform. This article is organised into six sections, which systematically explain how the aim and objectives are achieved.

This article is structured as follows: Section 2 describes the methods used to conduct this research. Section 3 summarises the literature by explaining the issues and limitations of BIPV projects and the current applications of blockchain technology in the construction industry. It also explains the knowledge gap. Section 4 explains the system architecture of a blockchain-enabled BIPV information management platform, considering a selected BIPV project and the system's ability to address the identified issues/limitations. It also explains about the system validation using semi-structured interviews. Section 5 discusses the blockchain application in BIPV projects. Section 6 provides the conclusion and future research directions.

The research design is shown in Figure 1. According to Figure 1, the study has used a literature review to identify the BIPV issues/limitations and potential blockchain applications in the construction sector. A case study is used to design and develop the blockchain platform to demonstrate its functions and how the platform has managed the BIPV issues/limitations. The developed platform is validated using semi-structured interviews.

A comprehensive literature review was carried out to identify the stakeholder issues related to BIPV uptake and potential areas for blockchain application in BIPV projects with reference to journal articles, conference papers, books, magazines and websites of professional institutes. Carefully selected keywords, Boolean operators, multiple scholarly databases and clearly defined inclusion and exclusion criteria were used to conduct the literature review. The goal was to identify relevant academic and technical publications related to blockchain technology, information management systems and BIPV. Scopus, Web of Science, ScienceDirect and Google Scholar were used to identify relevant peer-reviewed articles, conference proceedings and technical literature.

The search strings were developed to capture literature at the intersection of three primary themes: (1) blockchain technology, (2) information management systems and (3) BIPV. A representative search string used was:

The search limits included: (1) language: English, (2) publication years: 2013–2023, (3) document types: peer-reviewed journal articles, conference papers, book chapters and technical reports, and (4) subject areas: engineering, computer science, energy, buildings and architecture. Inclusion and exclusion criteria are as follows:

1. Studies discussing the application of blockchain in construction, renewable energy or information systems.

2. Articles focused on BIPV systems, including their design, deployment and integration.

3. Literature on digital or decentralised project management tools in the context of energy or building sectors.

1. Articles unrelated to the intersection of blockchain, BIPV or information management.

2. Studies solely focused on traditional photovoltaics without integration into buildings.

From the literature review, it was identified that there is limited published information about blockchain-enabled BIPV applications. Therefore, the study expanded the review to all construction projects. A significant number of recent studies were found on blockchain applications in the construction industry. Since BIPV is a construction method, the study assumes that the current blockchain applications in the construction sector can also be applied to BIPV projects. The study identifies 16 issues and limitations from the literature review. Further, the study explored how blockchain can be applied in BIPV projects to address the identified issues and limitations. Two main applications were identified as (1) blockchain-based information communication and management and (2) secured stakeholder integration and collaboration. The study also identified Hyperledger Fabric as the most appropriate blockchain type to address the identified issues.

The study used a BIPV project to demonstrate how a blockchain-enabled information system can address the issues and limitations identified from the literature review. The selected project was a development of a smart city consisting of BIPV buildings and PV landscaping in an island located in Taizhou, Jiangsu Province, China. The project had three main phases: (1) development of PV environmental attractions, (2) construction of net-zero energy buildings and (3) building a sculpture reflecting the city's sustainable targets. In phase 1, several PV environmental attractions were developed, such as a PV parking shed, a PV waste station, PV-enabled landscaping (lights and other) and a PV publicity gallery. Phase 2 included the construction of three net zero-energy buildings: (1) a café, (2) a smart house and (3) an off-grid conference centre. In addition, phase 2 included the renovation of an exhibition hall and the replacement of its facade with a BIPV façade. In Phase 3, the work included the development of a grand entrance, a city sculpture and necessary lighting, and beach landscaping. This study focuses on Phase 2 as it includes the construction of a BIPV façade and roof. The key reasons for selecting Project 1 for this study were as follows: (1) availability of details of BIPV design and construction, (2) multi-disciplinary and relatively high stakeholder involvement, (3) need for flawless communication and collaboration between the phases and concurrent work, (4) Project 1's timeline matched the timeline of the third objective of the present study and (5) the client's interest in having a better mechanism for information communication and management.

Project 1 had more than 2000 documents, including CAD drawings and SketchUp models with large document sizes (several MBs). The study focused only on BIPV-related documents; therefore, 438 documents were selected from the above document set. These 438 documents included many progress photographs; therefore, they were grouped into 12 folders, and each folder was considered as one document. Accordingly, the final BIPV-related document count was reduced to 120. These 120 documents were created in different stages of the BIPV life cycle. Considering the creator (sender or owner) and the receiver duo, the study divided the document set into four groups. The purpose of this division was to identify the communication channels. Accordingly, the proposed information management system consists of four channels dedicated to communication between the client–design consultant (channel 1), client-design consultant – contractor (channel 2), design consultant–supplier (channel 3) (only one supplier was selected to represent all suppliers) and client–facilities manager (channel 4).

Based on the above four channels, the blockchain-enabled BIPV information system was designed and developed using Hyperledger Fabric backend. The system operation was demonstrated using Project 1's documents. The system's ability to eliminate (or reduce) identified issues was evaluated.

The proposed blockchain-enabled information management system was developed as a private network with permissioned access. The front end was developed using Hypertext Markup Language (html), which is a standard markup language for designing web pages (Rebah et al., 2022). The study developed a user-friendly interface that provides access to different channels by simply logging in to the system. The backend of the system was developed using Hyperledger Fabric, one of the most advanced blockchain platforms with private transaction networks. The reason for selecting Hyperledger is its ability to deliver plug-and-play components such as consensus algorithms, member management and required privacy (Yang et al., 2020a). Also, it is more suitable for information management and record keeping of business cooperations that require internal privacy, such as construction projects.

The chaincodes (smart contracts) were written using JavaScript. The frontend and backend communicate with each other via the Java programming language. The Hyperledger Fabric is deployed on the Amazon Web Services (AWS) EC2 server. All project documents were stored in AWS S3 Cloud object storage to ensure access to documents from anywhere in the world (since Project 1 was located in China).

All organisations were registered during the development of the system according to their channels. If one organisation had access to several channels, it was registered under all these channels. The design consultant provided the names of all organisations that should be registered, along with their channel numbers, based on which registration was done. When accessing the system for the first time, every user can use their respective organisation to register in the system. The system is developed in such a way that it does not require the specification of the organisation of each user when logging in to the system for the second time onwards.

The purpose of validation is to confirm whether the system has delivered the stated outcomes, which would lead to eliminating or reducing the identified issues. Therefore, the researcher conducted three semi-structured interviews with three building-scale DSE stakeholders to validate the system. The selection criteria include (1) the interviewees should have experience in the BIPV industry for more than 10 years and (2) interviewees should represent diverse disciplines to collect different viewpoints.

According to Miles et al. (2018), the sample size depends on several factors, including the location of the research, the background and role of participants and their level of knowledge and experience. However, the general rule to decide the sample size in qualitative studies is information saturation, where no more new information is received from the participants. Malterud et al. (2016) proposed a new indication of an appropriate sample size called “information power”, which suggests that the amount of information provided by the participants and how relevant they are to the study could determine the number of participants. Considering all these aspects and the time constraints, three interviewees were selected for the validation who have expert knowledge and ample experience to comment on the platform. These stakeholders were asked to operate the blockchain-enabled BIPV information management platform and provide feedback on its performance, practicality and effectiveness. The researcher asked questions to confirm the validity of (1) the use of the overall system, (2) the system functions proposed in the prototype, (3) the ability to solve stakeholder issues, (4) the ability to deliver stakeholder expectations and (5) potential improvements. Table 1 provides the interviewee profile.

The study followed the stratified purposive sampling method to select the interviewees. This is a combined sampling technique which allows the selection of participants from predefined groups (strata) (i.e. builder, consultant, supplier) and then selected one highly experienced participant from each group (stratum) for validation. Interviewees were selected considering their reputation in their selected fields adhering to purposive sampling technique, which allows the researcher to select the participants most suitable for the study due to their knowledge and experience. The use of stratified purposive sampling enables coverage of all channels developed in the system and simplifies the recruitment process. Data collected from semi-structured interviews were analysed using NVivo software using priori coding based on a list of predefined codes. The research questions and problem statement supported the defined codes.

Multidisciplinary and multi-sector participation, long life cycle and high-risk involvement increase the complexity of construction projects (Turk and Klinc, 2017), and collaboration and communication are essential to manage this complexity (Shojaei, 2019). Digital assistance is highly required to deliver effective collaboration and flawless communication (Zhang et al., 2022). Blockchain technology can effectively provide the required digital assistance in many areas of construction projects.

A significant amount of research has been conducted to explore how blockchain can improve the construction process. Wang et al. (2020) developed a blockchain system to achieve information sharing, information management, real-time schedule control and information traceability in precast concrete element delivery to the construction site. Similarly, Wu et al. (2022) developed a blockchain-enabled framework to assure the accurate onsite assembly of modular construction. Zhong et al. (2020) and Sheng et al. (2020) explored the application of blockchain in construction quality information management by addressing issues such as information fraud and lack of transparency in available information. Yang et al. (2020a) explored the use of private and public blockchain systems to manage the procurement stage of a construction project, such as material purchase, equipment hires, etc and for design approval. Cheng et al. (2023) proposed an incentive-driven information sharing system for equipment leasing in the construction industry using a consortium blockchain. Brandin and Abrishami (2024) developed a real-time analysis and prediction model for off-site module manufacturing and supply chain operations by integrating blockchain technology with the Internet of Things (IoT) and building information modelling (BIM). Ye et al. (2025) explored the integration of the asset information model (AIM), IoT and blockchain for improved construction asset management. Zhang et al. (2023) explored the application of blockchain technology in construction contract management to assure effective information management, payment management and supply chain management. Wu et al. (2022) investigated the use of blockchain and smart contracts for on-site construction quality inspection and assurance. Singh et al. (2023) explored the adoption of blockchain-enabled BIM for facilities management. Das et al. (2022) explained the adoption of blockchain to protect document ownership in construction projects.

Many studies have explored the use of blockchain in solar photovoltaics applications. However, most of them discuss about blockchain-based peer-to-peer (P2P) renewable energy trading (Tushar et al., 2021; Zhou et al., 2020). Erol et al. (2021) investigated the use of blockchain technology to enable the circular economy and innovative renewable energy business models. Liu et al. (2022) developed a PV-storage-use value chain in a blockchain environment to enable a decentralised information flow between the PV prosumers, energy storage companies and energy consumers. Pipattanasomporn et al. (2019) discussed the use of a blockchain platform to exchange solar energy with neighbours. Tushar et al. (2021) explored how to form energy communities using blockchain technology.

Even though there are much research on blockchain application in construction industry and distributed solar energy industry, there are hardly any research on the use of blockchain in BIPV projects which is a combination of the above two industries. Multidisciplinary and multi-sector participation, long life cycle and high-risk involvement increase the complexity of BIPV projects and collaboration and communication are essential to manage this complexity (Wang et al., 2024). Blockchain platforms encourage digitalisation and decentralisation of information in an effective manner (Ali et al., 2021). Since the world is moving from traditional record keeping and face-to-face transactions, it is crucial to identify secure measures for systematic information management and stakeholder collaboration (Das et al., 2022; Pouttu et al., 2019). Blockchain fulfils this requirement by offering immutability and provenance to all transactions (Atlam et al., 2018). Hence, this study investigates how blockchain can be applied in BIPV projects. This study covers several research gaps, including (1) the lack of research on blockchain application in BIPV projects, (2) lack of investigation on how BIPV-related issues can be solved via information management and stakeholder integration and (3) lack of research on how to minimise the discrete nature of BIPV stakeholders. Most blockchain-related studies consider how to address information management and trust-related issues of the construction industry and trading and business model-related aspects of the solar energy sector. This study has a novel approach compared to the above research as it identifies many current issues related to BIPV projects and explores how to effectively address each issue using blockchain technology. Hence, this study provides an abundance of new knowledge to the BIPV sector. The blockchain prototype demonstrates how such a platform can be developed and what features need to be added to meet real-world requirements. The following sections discuss the literature findings of BIPV issues/limitations and potential applications of blockchain technology.

BIPV is currently recognised as one of the most effective methods of sustainable building construction (Osseweijer et al., 2018). It has many unique characteristics in comparison to rooftop PV applications, which can provide added value to a building. BIPV replaces building envelope materials. This material offset can reduce the total building costs in most situations (Gholami and Rostvik, 2020). It provides a better aesthetic appearance to a building with the availability of multiple colours, shapes and textures (Pelle et al., 2020). BIPV modules are not limited to the rooftop. They can be integrated with many building envelope materials and installed as façades, windows, balconies, canopies, walls and skylights (Martin-Chivelet et al., 2022). BIPV technology provides a mechanism to utilise the building envelope which is originally a dead space with no active functions and provides a building valuation uplift (Pelle et al., 2020). It also provides multiple functionalities, including the performance of building envelope functions, the provision of an aesthetic appearance and onsite energy generation (Lau et al., 2019).

Although the above characteristics make BIPV the better option, its design and management are relatively complicated. It is crucial to have a flawless design to acquire the maximum benefits of a BIPV building (Ning et al., 2018). The design should promptly and carefully address the architectural, aesthetic, electrical and civil engineering aspects in its design stage. This includes multidisciplinary involvement with diverse methodologies, techniques, aims and objectives (Jakica, 2018). For example, the architect's main goal is to achieve aesthetic excellence, whereas the PV consultant's main concern is to deliver efficient energy generation and economic O&M along the BIPV lifecycle (Wijeratne et al., 2019). Since BIPV replaces building envelope materials, the structural engineer's main concern is ensuring structural stability (Ikkurti and Saha, 2015), whereas the electrical engineer's concern is the design of a safe and flawless electrical layout (Yang et al., 2019). Most importantly, the building owner or the developer considers the building cost and value for money. Likewise, every stakeholder involved in the design stage has diverse concerns and the methodologies and techniques they use to successfully address these concerns are diverse. In addition, the duties and responsibilities of the stakeholders who are engaged in the later stages of the BIPV lifecycle will be significantly affected by decision-making in the design stage (Ning et al., 2018; Wijeratne et al., 2019).

The above explanation indicates that stakeholders face diverse issues when adopting BIPV technology. These issues prevent the rapid uptake of BIPV and the creation of a stable market for BIPV products (Kuhn et al., 2021). Therefore, BIPV is still a niche market in many countries. It is crucial to identify and address the above issues if we are to experience commercial growth in BIPV technologies and applications (Vroon et al., 2022). A comprehensive literature review has identified 16 main stakeholder issues of BIPV adoption. They are summarised in Table 2.

BIPV projects often have to follow two sets of regulations: (1) local and international building codes and standards and (2) local and international electrical codes and standards (Chen et al., 2022). Many local and international building and electrical codes, regulations and standards currently available around the world are applicable to all PV applications (Ko et al., 2022). For example, the relevant standards provided by the International Standards Organisation (ISO) and the International Electrotechnical Commission (IEC) are commonly applied to BIPV projects (Chen et al., 2022). A detailed regulatory framework and standards specific to BIPV are hard to find around the world (Attoye et al., 2022). For instance, there is no precise regulation for PV panels replacing conventional building envelope materials (Singh et al., 2022). Similarly, there are no specific regulations for BIPV electrical safety and fire prevention (Agathokleous and Kalogirou, 2020). The lack of uniform regulations and standards is often a risk when importing BIPV modules and BOS components from one country to another (Ballif et al., 2018).

Stakeholders along the BIPV lifecycle do not have adequate access to product information to carry out their duties (D'Amnrosio et al., 2021). In particular, it is very difficult to determine product costs and installation costs to conduct an accurate economic analysis prior to the selection of a BIPV system (Corti and Bonomo, 2022, Jakica et al., 2019). In most countries, there is no convenient way (i.e. a product database) to find out all local products without going through a time-consuming search (Wijeratne et al., 2019). An information gap can be seen between the BIPV module manufacturers and building designers as they are not kept up-to-date on module types, new innovations, market trends and economic benefits (Bognar et al., 2019).

Due to multi-sector involvement and the long lifecycle, stakeholders in BIPV projects are not well-connected with each other (Yang and Zou, 2016). Currently, there is little collaboration between the building and PV industries when designing a BIPV project (Osseweijer et al., 2018). Surprisingly, about 80% of the decisions that affect the energy performance of a building are currently taken by architects in the early phase of design and PV consultants are not involved (Freitas et al., 2020). One of the main reasons for such action is the lack of communication and the lack of collaboration between BIPV stakeholders in the design stage (Yang et al., 2019). This generates discrepancies between the design and the actual installation. There is no detailed communication between the design team and the stakeholders in the later stages of the BIPV life cycle; therefore, on most occasions, O&M procedures generate unnecessary costs (Ning et al., 2018). If maintenance officers are not familiar with the design and commissioning, they will face difficulties in maintaining system performance with limited expenditure (Jakica, 2018).

BIPV is a comparatively new technology to the building industry and its uptake has been very slow (Weerasinghe et al., 2021a). Hence, there are insufficient professional experts and skilled labour to encourage its adoption (Ekung et al., 2020). Qualified BIPV designers, specialised contractors and installers are difficult to find in many countries (Tan et al., 2021). Integration of BIPV modules into a building envelope is a complex process and should be carried out as per the building and electrical codes and safety requirements (Wijeratne et al., 2022). The installers should have a detailed understanding of building envelope construction, electrical connection and fire prevention requirements. Architects should collaborate with BIPV experts to finalise the design to ensure optimal BIPV performance (Osseweijer et al., 2018). Facilities managers and O&M teams should have the knowledge and skills to operate and maintain the systems (Weerasinghe et al., 2021b). There is a lack of education and training courses to produce BIPV professionals and skilled labour around the world, which has become one of the main reasons for the lack of sufficient skilled professionals (Yang et al., 2019).

Many stakeholders have inadequate knowledge and awareness of BIPV products, their benefits and related applications (Weerasinghe et al., 2021a). Common reasons include the unavailability of (1) information sources and (2) methods of knowledge transfer between stakeholders (IEA, 2019). Architects and builders are reluctant to engage in BIPV projects or recommend BIPV to their clients due to insufficient knowledge and understanding (Weerasinghe et al., 2021b). Currently, many BIPV products are available in different colours and textures, and with high efficiency (Eder et al., 2019). In addition, many new products and suppliers are coming into the market every day. The issue is that stakeholders do not have access to information about the latest products and their performance, especially with no BIPV product databases being readily available for public access (Wijeratne et al., 2019).

One of the key stakeholder issues is that there are no BIPV-specific government incentives or financial schemes to provide monetary help to investors (Curtius, 2018). Most governments offer renewable energy incentives common to all renewable energy adoptions; however, they do not specifically encourage building owners to select BIPV solutions instead of rooftop PV (Attoye et al., 2022). Therefore, BIPV-specific policies and incentives are crucial to encourage adoption. In addition to monetary assistance, governments can provide support for technology endorsement, promotion and legitimation by providing a sound legal framework, supporting BIPV-related R&D and conducting promotion campaigns (Yang et al., 2019).

Blockchain can deliver two main types of services in the construction sector: (1) information sharing and management and (2) stakeholder collaboration (Das et al., 2022; Mohammed et al., 2021). Since BIPV projects follow the same lifecycle as any building construction, the above services can be applied to BIPV projects.

BIPV is a comparatively new technology (Taşer et al., 2023). Therefore, a great deal of new information is being released worldwide about new products, technologies and applications (Corti and Bonomo, 2022). Clients, architects and BIPV designers should have a clear understanding of these new products prior to using the technology in building design (Yang et al., 2019). Since it is an active type of solar building envelope construction, information such as fire safety, energy performance, product certification, warranties, testing outcomes, product standards and manufacturer's information is essential to develop optimal BIPV designs (Wijeratne et al., 2019). BIPV projects have a great deal of documentation and information that need to be provided to different stakeholders. Since BIPV has a long lifecycle, flawless information communication and management should be available along the lifecycle; if this is not the case, the O&M process will be difficult and inefficient (Jakica, 2018; Ning et al., 2018). Typically, following information management requirements can be summarised. Information such as drawings, specifications and product information should be shared with several stakeholders. Some information, such as product costs and supplier quotations, should be confidential and should not be seen by other suppliers. Some documents, such as the conceptual design and cost plans, have continuous updates and revisions that must be communicated efficiently. Some information should be cross-checked with other information (e.g. imported BIPV module standards should be cross-checked with local standards). At the end of each lifecycle stage, all relevant documents should be passed to the party responsible for the next stage. Most stakeholders are not available throughout the whole BIPV lifecycle. Their duties are specific to one or more stages, but not all of them. Therefore, the information produced by these stakeholders should be available to other stakeholders, even if they are no longer working on the project. Architects and BIPV designers have concerns about breaching the ownership and copyright of their innovative designs. Therefore, ownership of the documents should always be protected.

A blockchain platform equipped with DLT, smart contracts, a consensus mechanism and cryptographic access can deliver all the above aspects of BIPV information management (Iredale, 2021). Based on the nature of the project, stakeholder involvement, information management requirements and the nature of the above issues and limitations, Hyperledger Fabric is considered to be the most suitable blockchain platform type. This is confirmed by many studies that have adopted the same platform type for information management in diverse construction fields (Das et al., 2022; Mohammed et al., 2021; Pan et al., 2022; Zhang et al., 2022; Zheng and Lu, 2022). Hyperledger can provide separate channels for secure, confidential communication (Yang et al., 2020a) and maximum flexibility to implement the preferred system architecture (Hyperledger Foundation, 2022). In addition, since Hyperledger is a permissioned blockchain type; therefore, access to information can be controlled (Duca et al., 2020). Hyperledger is considered to be one of the most sophisticated blockchain platforms with comparatively low latency and high throughput (Xu et al., 2021); therefore, it facilitates speedy information transactions. These characteristics make Hyperledger suitable for information management and communication.

BIPV stakeholders should maintain three types of collaborations: (1) between stakeholders of a single sector (e.g. stakeholders in the building sector) (2) cross-sector (e.g. stakeholders of PV and building sectors) and (3) stage-to-stage of the BIPV lifecycle (e.g. from the design stage to the procurement stage). Hyperledger Fabric provides adequate modularity and versatility to deliver the above types of collaborations (Abbas et al., 2020; Elghaish et al., 2022). Hyperledger can assign different channels to facilitate the above types of collaboration (Yang et al., 2020a). Permission to access these channels will be given only to those parties who need collaboration (Bhalla, 2022). The system architecture can be designed to maintain diverse collaborative groups, such as (1) client-architect-builder, (2) architect-suppliers, (3) architect-design consultants and (4) client-facilities manager. They can exchange sensitive information and ensure the privacy of communication (Das et al., 2022). The participants in a single channel will be able to read and/or write transactions based on their permission conditions (Yang et al., 2020a). For example, some participants can just be observers who can only read the transactions performed in the channel, whereas some participants can conduct transactions and read them. This is an effective technique to ensure the security and ownership of documents (Turk and Klinc, 2017). The observers do not have the right to endorse the transactions; therefore, in the platform, there are specified participants who can endorse a transaction (Yang et al., 2020a). While providing the necessary document security, this technique also reduces latency and improves transaction throughput (Xu et al., 2021).

According to the explanations of the above two sections, Hyperledger Fabric-based blockchain platform is suitable for BIPV information sharing and management and stakeholder integration and collaboration.

Hyperledger Fabric was developed as an advance of blockchain technology and launched by the Linux Foundation in late 2015 (Zhong et al., 2020). It is a modular platform (permissioned, private) that supports cross-industry blockchain applications (Sheng et al., 2020). Hyperledger Fabric is currently sponsored by diverse corporations, including Linux Foundation, IBM and many other organisations (Bhalla, 2022). It is considered to be one of the most refined blockchain platforms available to date and is the first platform that supports multi-language (Java, Node.js, Go) smart contracts (Yang et al., 2020a). Hyperledger Fabric delivers plug-and-play components such as consensus algorithms, member management and privacy. The following are some design components incorporated in Hyperledger Fabric.

In Hyperledger, smart contracts are called chaincodes. They dictate how an asset is created and maintained in the world state (Aggarwal and Kumar, 2021). Chaincode is a software component used in Hyperledger Fabric to gather one or more smart contracts together to be installed in a specific channel (Yang et al., 2020a). Chaincodes have different methods to make a change to an asset and question its current state. An endorsement policy is defined when installing a chaincode, which decides the peers who have the right to endorse and validate a transaction. The key feature of Hyperledger Fabric is the ability to maintain a network of networks (Hyperledger Foundation, 2022). This means that the members of a network who work together for a common purpose can have the privacy they require in certain situations. For example, a business that conducts many purchases and deals with different suppliers who sell the same products should protect their privacy in order not to harm their competition. This is enabled by the “channels” feature of Hyperledger Fabric (Zhong et al., 2020). The platform can provide different communication layers for different groups of participants to maintain the privacy of data transactions. Blockchain is a journal that contains the transactions that occur in the channel (Aggarwal and Kumar, 2021). Blockchain ledger cannot be amended or adjusted by any individual. An authorised participant can check the content of any transaction chain recorded in the journal from its initial state to the current state (Li et al., 2019).

Membership Service Provider (MSP) is responsible for providing peers with cryptographic identities (Androulaki et al., 2018). MSPs maintain the permissioned access to the blockchain network (Yang et al., 2020a). The MSP uses a certificate authority (CA) to validate and confirm each node (Li et al., 2019).

Hyperledger Fabric has an execute-order-validate architecture (Ruan et al., 2020). This means that in a Hyperledger platform, a transaction happens in three phases. In the first phase, a client sends a transaction proposal to a set of peers who are specified by an endorsement policy (Yang et al., 2020a). The peers execute the transaction and record its effects in terms of read and written states (Androulaki et al., 2018). In the second phase, the orderers (ordering services nodes) collect the new transaction and determine its order and the overall order of all transactions (Yang et al., 2020a). This order is announced to all peers so that in the third phase, each peer validates the transaction and its sequence with regard to a predefined set of rules (Ruan et al., 2020). All nodes in Hyperledger platforms have a separate identity which can be categorised under three main roles (Androulaki et al., 2018): (1) client's role–sending transaction proposals for execution, ordering and validation, (2) peer's role–executing transaction proposal and validating the transaction and (3) orderer's role–collecting transactions into blocks for distribution and establishing their overall order.

Hyperledger is associated with versatility for diverse industrial cases (Hyperledger Foundation, 2022). It is more suitable for information management and record keeping of business cooperations that require internal privacy (Duca et al., 2020). This study has identified the suitability of Hyperledger Fabric for information management in BIPV projects, which have diverse stakeholder groups and demand a certain level of data privacy (Abbas et al., 2020; Elghaish et al., 2022). Further, record keeping is essentially required for the management of long BIPV lifecycles; therefore, having a decentralised record keeping system with controlled access is an additional advantage to eliminate information gaps.

Project 1 is a very large project with different types of constructions and many associated documents. In addition, there were many stakeholders who needed to communicate via this platform, which made the development of the platform complicated and time-consuming. Due to the time constraints, this study only considers BIPV-related work elements in Project 1 (Phase 2) and develops a prototype of a blockchain-enabled information management platform. The design process of the platform included several steps: (1) stakeholder requirements extraction, (2) sorting out the information to be uploaded to the system, (3) identifying the functions of the system and (4) designing the system architecture. These steps are explained in the following sections.

Phase 2 of Project 1 included the design and development of three buildings and the renovation of the façade of one building. All of these buildings had BIPV roofs or façades. As the design consultant and the main contractor were experts in BIPV design and development, they led the project. Other stakeholders, including suppliers, subcontractors and facilities managers, joined the project at different stages of its lifecycle.

Project 1 used two Microsoft Excel sheets to keep records of the stakeholders and their roles in the project. One Excel sheet summarised the parties involved in each major work element of Project 1 and the details of their agreements with the client or any other party (e.g. agreements between the design consultant and suppliers, agreements between the main contractor and subcontractors, etc.). The other Excel sheet showed the main work elements, the responsible parties and their details and work progress. Using these two documents, the study identified the BIPV stakeholders and their communication patterns, which are summarised in Table 3.

The study received access to the Cloud folder of Project 1 in which all project documents were stored. However, they were not stored systematically according to the project phases or major construction elements. Therefore, the study initially sorted out and summarised all information on a Microsoft Excel sheet using the format given in Table 4. The purpose of this summary was to identify the documents related to BIPV design and construction.

The functions of the blockchain-enabled information management platform were identified based on two sources: (1) the client's expectations of the platform and (2) the weaknesses and issues identified in the prevailing information management system. The client's expectation was to have a user-friendly platform to facilitate stakeholder communication, information sharing and systematic recording. The client preferred a system that could easily provide stakeholders access to the required information with limited time and effort, although the document owners have left the project. He also preferred to have the option of privacy since some communications in the project were private and confidential.

The study identified several weaknesses of the original information management system. It lacked systematic record-keeping. Some documents were duplicated in several sub-folders. Revisions of the documents (if any) were not clearly labelled. Some documents had unidentifiable names, which did not indicate their content. Some basic documents, such as work schedules, product brochures and product warranties were not available in the system and there was very limited information related to stakeholder communication. The main reason for not having communication information was that it was done separately via email. It was sometimes difficult to identify the ownership of documents and who did the revisions. There was no way to identify whether a document had been deleted from the system. Access to information was given by sharing a folder; however, since this folder contained all information, it was difficult to ensure the security and authenticity of documents.

Considering all the above details, this study summarised the functions of blockchain-enabled information systems as follows: (1) information sharing, (2) communication, (3) information storage, (4) information security and authentication. Figure 2 shows the main tasks under the above functions that could be done using the proposed information platform.

Considering the creator (sender/owner) and the receiver duo, the study divided the selected 120 documents into four groups. The purpose of this division was to identify the communication channels. Accordingly, the proposed information management system consists of four channels dedicated to communication between the client and design consultant (channel 1), client and design consultant and contractor (channel 2), design consultant and supplier (channel 3) (only one supplier was selected to represent all the suppliers), and client and facilities manager (channel 4). The primary network structure developed considering the above details is shown in Figure 3.

Figure 4 displays the system architecture of the proposed blockchain-enabled information system. It consists of two key layers: the front end (interface) and the backend (Hyperledger network). The front end is designed to provide access to information by logging in to each private channel and doing the necessary transactions. The study designed a simple front-end that can be used by any project stakeholder without requiring IT knowledge.

The back end was developed using Hyperledger fabric. The network consists of four channels dedicated to communication between 5 stakeholder organisations. The design consultant and the client have access to three channels. The other parties (contractor, PV storage system supplier and the facilities manager) have access to only one channel. In addition, there is an ordering service organisation (orderer) to ensure that consensus is achieved between all the peers. The orderer has access to all channels. The orderer's responsibility is to collect transactions from the peers and determine the overall order of all transactions. Therefore, the orderer acts as the administration point and supports all channels to order transactions in blocks for dissemination.

The proposed blockchain-based information management system was designed based on the requirements of the client and the design consultant. Since the design consultant engaged more with the project, the study assigned the design consultant and one network administrator as the network initiators. The design consultant provided the requirements of the system and based on these requirements; the network administrator initiated the network.

The access privilege of a particular channel is restricted. Only participating users of a specific channel can access the ledger. Each organisation has its own MSP, denoted by Org1.MSP–Org5.MSP, to deliver a provider certificate to a certificate authority outside the network to confirm the authenticity of its membership of the channel. The organisations in every channel can approve transactions as per the predefined chaincode (smart contract) in the channel. Every channel has a ledger to record the transactions. The network also has peer nodes, which act as virtual staff working on the ledger. Each organisation has a peer node dedicated to it. These peer nodes have copies of the ledgers according to the involvement of the organisations in each channel. For example, P1, which represents the client organisation, maintains a copy of ledger L1 related to channel 1 and ledger L4 related to channel 4. P2, which represents the design consultant organisation, maintains a copy of ledger L1 related to channel 1, ledger L2 related to channel 2 and ledger L3 related to channel 3. P3, which represents the contractor organisation, maintains a copy of ledger L2 related to channel 2. P4, which represents the PV storage supplier organisation, maintains a copy of ledger L3 related to Channel 3. Finally, P5, which represents the facilities management organisation, maintains a copy of ledger L4 related to channel 4. The Hyperledger backend and the interface are connected via a server.

System operation is discussed under the following five main functions: (1) information sharing, (2) communication, (3) information storage, (4) information security and authentication and (5) BIPV-based energy generation monitoring.

Information sharing is one of the key targets of blockchain-enabled information management systems. The requirement is to share information with other stakeholders on a common platform to avoid information gaps. Any member in one channel can share their documents with other members in the channel. An option is available in the platform homepage (represented by the “+” icon) to upload the documents to the system. Information about the documents can be added manually when uploading the documents to the system, as shown in Figure 5. When a document is uploaded to the system, its details can be found in both card view and table view; however, table view provides additional information in comparison to the card view, including the developer and owner of the document and the date and time when it was uploaded.

All documents in Project 1 were uploaded to AWS S3 Cloud object storage; therefore, only the document link was added to the platform. Every participating organisation uploads their document set to such Cloud storage and only uploads the document link to the platform. This method delivers a solution to capacity limitations blockchain platforms. Since most Project 1 documents are large in size, it was important to deliver a practical solution to capacity constraints.

Whenever a member wants to access a document, s/he can copy the document link and paste it into the web browser to read it. A demonstration is given in Figure 6. This document can be downloaded for personal use; however, cannot be changed in web view.

If a member downloads a document that was not created by him/her, s/he can change it; however, the changes must be uploaded as a new document under a new document ID. This method secures the document's copyright and ownership, as the document log shows who initially created the document and its original version. If the document owner wants to make some revisions to a document, the revised version should also be added as a new document under a new ID. However, the document name can remain the same, and when uploading the document, an explanation can be given under the tab “main content” that the new document is a revision of a previous document. An example is given in Figure 7.

The system allows communication between members by sending a document to another member in the channel along with an action request (edit/sign/ use the document to prepare a new document, etc.). This is called transferring documents. By sending the document, the original owner gives ownership of the document to the receiver under the endorsement of the channel. Once a document is transferred, the original owner cannot further transfer it to a third member (in channel 2) or delete the original document. However, the new owner (document receiver) can do both of these actions. The important part of transferring documents is the transaction record. The transaction record shows that the document has now been given to another party for their changes. Once the receiving party completes editing the document, it is uploaded as a new document and sent back to the original owner, returning his/her ownership. This can be demonstrated by an example. The contractor is communicating with the design consultant about signing the engineering contract. S/he follows the steps shown in Figure 8.

The system enables the above communication as follows: The contractor uploads the unsigned engineering contract to channel 2. He then transfers the contract to the design consultant (Document ID – D-04). The design consultant downloads the document, includes his signature and stamp, and uploads the document using the same name, describing it as signed by the design consultant. The uploaded document has a new ID (D-05) as it is no longer the unsigned contract document. Next, the design consultant transfers document D-05 to the contractor. The contractor downloads it, includes his signature and stamp and uploads the final contract document to the system with a new ID: D-06. The process is similar to communicating by email, but much safer, as the records of all the above transactions are stored in the system in chronological order and cannot be deleted without any acknowledgement. Document transfer is done using the bottom left icon given in each document card, as shown in Figure 9. Figures 10–15 show the process of document transfer in the system according to the communication process shown in Figure 8.

The system allows communication between the members in one channel. It does not facilitate communication between channels.

The system keeps a record of every document transaction in the channel. The summarised version of the records is the card view (as shown in Figure 15), and the detailed version is the table view (as shown in Figure 16). In the table view, information such as document ID, main content, document link, project stage, document type, document size, sent by, received by, date received, last modification and the transfer message is listed. When a member uploads a document, it is recorded in the “received by” column. This means that the specific document was received by the system on a certain date and time. This date and time are recorded under the “last modification” column. If this document is transferred to another member, the document owner becomes the sender (recorded under the “sent by” column) and the receiving party becomes the receiver (recorded under the “received by” column). The date and time of this transaction are recorded under the “date received” column. This column is only used to record the date and time when a document is transferred. Whether a document is uploaded or transferred, the date and time are recorded in the “last modification” column. The above information cannot be changed in any way. Whenever a transaction occurs, it is recorded in chronological order, providing clear details of the document's line of communication. The ownership of the document is clearly visible in the card view (or can be found out from the table view) as the card includes (1) the owner's name and (2) two icons at the bottom to transfer and delete. These two icons are available on a card only if it is owned by the stated member. Figure 16 demonstrates the difference between the two cards.

The system provides information security and authentication in several ways: (1) by tracking every transaction, (2) by time stamping transactions and (3) restricting and acknowledging the deletion of documents. Tracking transactions and time stamping can be clearly seen in the table view as shown in Figure 16 (interface). It is also available in the backend Hyperledger network. The ledger of each channel records all transactions in separate blocks with a unique hash value (unique identifier) to distinguish them from the next block. In addition, the hash value of each block maintains the connection between the two nearest blocks. It is a fixed-length code that is difficult to identify or guess; therefore, tampering with the blocks is almost impossible. This structure provides maximum security to document transactions and protects their integrity. Since the document view is a web view, it cannot be edited. Although any member can download the documents and make changes, they cannot upload the edited document under the same document ID. In this way, the system avoids document tampering, exploitation and unauthorised duplication.

The system has a full record of the ownership of a document, even though it may be transferred to other members several times. The record history shows who first uploaded the document to the system, which confirms the ownership of the document; therefore, members do not have to be concerned about copyright and ownership. The system allows only the owner to delete a document, and this is also recorded in the system. A document can be deleted using the right-bottom delete icon of the card view, as shown in Figure 17. Although the document is deleted, it is still available in the platform under “deleted assets”, as shown in Figure 18. Every member in the channel can see the deleted assets; therefore, deletion cannot be done without informing the other members of the channel. However, the document cannot be seen in card view or table view when it is deleted.

One of the most important actions in the operation stage of a BIPV building is energy generation monitoring. It will give the building owner a clear idea on the return of their investment. The proposed system has a separate channel (channel 4) dedicated to communication between the building owner/user and facilities manager. The facilities manager can upload the monthly BIPV-based energy generation to channel 4 so that the building owner has a proper record of the energy generation. This approach provides a number of benefits, including (1) the ability to compare monthly generation, (2) a visual record to understand how energy generation fluctuates throughout a month and eventually the whole year, (3) ability to identify issues of the system and (4) no information gaps between the building owner and the facilities manager. Figure 19 shows the energy records of Project 1 uploaded to Channel 4.

Most stakeholder issues are effectively addressed by the information management system of Project 1. However, several issues cannot be fully eliminated or directly addressed by the system. Table 5 summarises how the prototype addresses these issues.

The three interviewees agreed that the prototype of the blockchain-based information management system delivers a sufficient level of decentralisation for BIPV information communication and sharing. Interviewee 2, a BIPV designer, stated that it is a timely requirement to identify decentralised methods for information communication in BIPV projects, where everything relies on information. Interviewee 1, a project manager, felt that the prototype considers the basic communication patterns along the BIPV supply chain and effectively demonstrates the ability to provide secure, reliable and efficient information recording, communication and sharing. All interviewees agreed that BIPV information management should have adequate privacy despite using decentralised measures, and therefore confirmed the use of separate channels for stakeholder collaboration. Interviewee 3 pointed out that secure information sharing can limit conflicts and disputes among stakeholders and provide a solid record of transactions. According to Interviewees 1 and 2 (project manager and BIPV designer), dealing with document revisions and constant updates is difficult and often creates errors; however, this prototype avoids the above complications by eliminating document duplication and providing correct document identification. The three interviewees recognised the prototype as an important innovation and assured its future adoption in the commercial context.

In the prototype, there are four basic functions: (1) information sharing, (2) stakeholder communication (collaboration), (3) record keeping and (4) document tracking. All interviewees agreed on the above functions and confirmed that they can be effectively delivered via the system. According to Interviewee 2, the ability to transfer documents with simple notes is effective for making instant queries about designs and delivering rapid responses. According to Interviewee 1, the table view of the prototype provides a database of project documents, which is very useful for finding relevant documents easily. According to Interviewee 2, the system only allows document owners to make changes; therefore, architects and BIPV designers do not have to be concerned about the ownership and copyright of documents. Similarly, the responsible parties for documents are clearly defined in the system; therefore, the stakeholders know whom to contact if there is a discrepancy or dispute. According to Interviewee 3, BIPV projects have multiple sectors working together; therefore, decentralised communication can facilitate teamwork. All three interviewees confirmed that the functions provided by the prototype are useful to any BIPV project.

According to all interviewees, the functions of the prototype are able to solve many issues in BIPV projects. According to Interviewee 1, the most common issue with BIPV projects is a lack of stakeholder collaboration, and the prototype solves this issue by delivering a decentralised platform for secure communication. Interviewee 2 revealed that BIPV designers often find design-related issues which need to be sorted out promptly; however, due to the high workload of every stakeholder, correspondence is very slow. Interviewee 2 confirmed the prototype's ability to solve this issue through the document transfer function. Interviewee 3 stated that the prototype solves the issue of a lack of product information, as PV/BIPV suppliers have a secure platform to share product information such as costs, specifications, warranties, product certifications and testing outcomes. Interviewee 1 identified the assistance the prototype would provide in receiving and send information to relevant parties. Interviewee 1 pointed out the possibility of collaborating with external parties such as councils and building authorities to check product and design compliance as per the building codes, electrical codes, standards and fire safety aspects. All interviewees confirmed the prototype's ability to solve issues such as a lack of stakeholder trust and acceptance and a lack of awareness about cross-sector work responsibilities. The researcher asked about the system's ability to deliver adequate governance, and the interviewees responded positively.

The above section discussed how blockchain technology is used to address the stakeholder issues and limitation of BIPV projects. The direct or partial solutions to the issues and limitations are generated by the features and functions of blockchain technology, such as smart contracts, consensus mechanism, DLT and digital signature. The solutions include (1) information accuracy and reliability, (2) information security, (3) necessary access to information (permissioned), (4) systematic record keeping and (5) system governance. These solutions increase stakeholder trust and acceptance of DSE applications.

Information accuracy and reliability: Blockchain is instrumental in delivering information accuracy and reliability via its diverse technological features (Pan et al., 2022). Information accuracy and integrity are achieved via the characteristics of the Hyperledger blockchain platform (Suliyanti and Sari, 2020). All document transactions in the information system of Project 1 are recorded in separate blocks with unique hash values to prevent data tampering. Access is controlled by a certificate and cryptographic authentication. The content of documents cannot be changed without informing all other members of the channel. Any change to a document is recorded in the system. Changes can only be made by downloading the document; however, it must be uploaded as a new document with a new ID to show the difference. Documents can be deleted only by the document owner. Deleted documents are visible to all members of the channel under the “deleted assets” tab.

Information security: As explained above, private blockchains are adopted to develop systems to deliver privacy and security to documents. Only the members of the relevant channel can see the documents. Tao et al. (2021) emphasise the importance of private channels to transfer information that may affect copyright, trade secrets and supplier competition. Since the information system of Project 1 acknowledges the above importance, it creates separate channels to support the privacy and confidentiality of information. Every member has a unique username and password to enter the system. Das et al. (2022) and Tao et al. (2021) have shown in detail how document IDs are assigned to each document transaction in their blockchain system architecture. In the present study's blockchain system only the document links are given in the system. Documents are stored in Cloud storage to which access is not given. The document link only opens the document in a web browser; therefore, there is no possibility of tampering with the content. All changes to documents are recorded in the system.

Necessary access to project information: Sometimes, decentralised information systems require permissioned access to avoid privacy and copyright violations (Berdik et al., 2021). According to Eder et al. (2019), BIPV suppliers are reluctant to exchange product information due to the lack of integrity in communication networks. Therefore, BIPV projects do not require open access to information. However, adequate and necessary access to information should be delivered based on the most common stakeholder relationships. This study's information system does not provide open access to all project information. It only provides access to information relevant to stakeholders. The channels were developed considering the communication patterns of the stakeholders. For example, channel 2 was created to share project information between the client, contractor, and the design consultant. This enables open communication and document sharing between the three main parties of Project 1. Most of the project's documents are shared in this channel. The channels, such as channel 3, allow communication between different sectors.

Systematic record keeping: Das et al. (2022) and Yang et al. (2020a) refer to the importance of systematic record keeping of construction documents to avoid delays, discrepancies and errors. BIPV projects have information coming from diverse sectors, which need to be cross-checked with other documents and delivered to multiple parties (Curtius, 2018). The blockchain system of Project 1 records all document transactions in chronological order. Every transaction is time-stamped to identify the order of receipt and recorded with supplementary information such as document type, main content, document size and sender-receiver details. The table view in the system provides all this information in one place.

Adequate system governance: Das et al. (2022) and Tao et al. (2021) discuss blockchain's ability to deliver adequate system governance. The present study has also recognised this ability and emphasised Hyperledger Fabric's ability to deliver project-specific governance. The system of Project 1 was developed according to the project requirements. The transactions are governed by the chaincodes, which contain a pre-defined set of rules on how the transactions should be done. Therefore, the system has careful governance. In addition, the interface dictates some basic rules such as registering for the first time, logging in with username and password, no access to channels that have no membership and access to multiple channels with membership.

Blockchain-based information management systems in construction show strong promise in enhancing security (immutability, tamper detection), efficiency (automated workflows, reduced disputes) and transparency (Shared ledger). However, scalability remains a key constraint. Solutions like Hyperledger Fabric help, but large-scale implementation requires careful performance design. When comparing the scalability of blockchain-based information management systems in construction projects, many studies reveal distinct capabilities and limitations. The information management system of this study uses Hyperledger fabric to improve scalability with the arrangement of permissioned access, channel architecture and private data collection (off-chain). Even though the proposed system of this study can handle a small number of BIPV stakeholders, it is difficult to assure its performance in a mega BIPV project with numerous stakeholders. Similar to this study, Wong et al. (2021) proposed a document management framework using Hyperledger Fabric, which supports P2P interactions but has yet to be validated for large-scale, multi-stakeholder projects, leaving its scalability largely theoretical. Similarly, Zhang et al. (2020) developed a system for managing construction quality data, demonstrating potential for small-scale implementation, though the system's reliance on consensus mechanisms may hinder performance under heavy data loads. In contrast, Song et al. (2023) presented a fund management platform tested in a large real-world infrastructure project, showing that scalability can be achieved with careful system architecture and stakeholder coordination. Overall, while progress is evident, achieving true scalability across complex construction ecosystems requires further technological refinement and real-world validation.

The security features of the blockchain-based information management systems proposed across many studies reveal common strengths to this study. However, some unique focuses tailored to their specific applications can also be seen. The proposed system in this study provided security via Hyperledger Fabric's permissioned architecture, utilising robust access control mechanisms, certificate authorities and cryptographic hashing to ensure data immutability, integrity and controlled access to sensitive BIPV documents and cost records. Nevertheless, this study did not focus on complex security measures beyond the common blockchain features. In Song et al. (2023), the researchers extend security by employing smart contracts for automating payment workflows, enhancing financial transparency and reducing fraud risk, though this introduces potential vulnerabilities inherent to smart contract coding errors. Saah et al. (2023) combine blockchain with cloud encryption and privacy-preserving protocols, emphasising the protection of sensitive worker data and regulatory compliance, but at the cost of increased complexity and potential cloud security risks. Celík et al. (2024) highlight that while immutability, encryption and access control are foundational across systems, challenges still continue around smart contract vulnerabilities, identity management and insider threats. Overall, these systems collectively underscore blockchain's capacity to significantly enhance security in information management; however, implementation details such as smart contract auditing and secure cloud integration remain critical to fully realising this potential.

The efficiency of the blockchain-based information management systems discussed in many studies varies depending on their application focus and system architecture. Most of the studies, including this study, complement the improved efficiency in document handling through automated control and decentralised access, reducing administrative overhead and delays in information exchange. Zhang et al. (2020) streamline quality management processes by automating approvals and tracking through smart contracts, which enhances workflow speed and reduces manual intervention. Saah et al. (2023) integrate blockchain with cloud-based infrastructure to manage worker data in real time, enabling fast updates and efficient data retrieval; however, the study also recognises the potential latency and cost trade-offs. Celík et al. (2024) explain that while blockchain generally enhances process transparency and reduces redundancy, many systems still struggle with high energy consumption, consensus delays and the lack of streamlined integration with existing construction software. Overall, the studies show that blockchain can enhance efficiency across different construction processes, but its full potential depends on the balance between decentralisation, processing speed and infrastructure design.

The implementation challenges of the proposed information system highlight a range of technical, organisational and operational barriers that hinder its uptake. It is difficult to point out who will be operating and maintaining the information system as each BIPV project is a temporary collaboration of diverse professions in diverse sectors. Construction industry is often reluctant to adopt new technologies; hence, the stakeholder acceptance cannot be guaranteed. The performance of the system will highly depend on the number of parties involved, amount of information to be communicated and ability of professions to use the system. Similarly, Kiu et al. (2024) present a broader perspective, identifying high setup and operational costs, low technological maturity and organisational resistance as critical obstacles, especially in firms unfamiliar with blockchain technologies. Das et al. (2022) emphasise the complexity of integrating blockchain with distributed file systems like InterPlanetary File System (IPFS), noting concerns related to data synchronisation, storage overhead and limited real-world testing at project scale. The study also points to interoperability issues with existing Electronic Document Management (EDM) systems, which often lack the flexibility to incorporate decentralised architectures. Yang et al. (2020b) further explore the trade-offs between public and private blockchains, revealing that although private networks are more scalable and secure, they involve significant challenges in governance design, stakeholder onboarding and long-term system maintenance. Collectively, these studies underscore that while blockchain offers strong potential for improving information management in construction, its practical implementation is constrained by technical limitations, organisational readiness and the need for tailored deployment strategies that align with specific project contexts and stakeholder capacities.

This study explores the potential opportunities for blockchain applications in BIPV projects to enhance trust, transparency and the reliability of information sharing and communication. The study identifies several issues and limitations that hinder the widespread adoption of BIPV technology and reduce stakeholder trust. It examines whether blockchain can address these challenges, and if so, in what ways and to what extent it can effectively do so. The primary objective of this study is to investigate how blockchain can improve information sharing and communication within BIPV projects. However, there are several limitations to this study, which are discussed in the following sections.

The nature of the issues and limitations identified in this study indicates that they are deeply embedded in strategic, legislative and business cultural factors, rather than technical limitations that could be addressed through the implementation of a blockchain-based information system. Most of these issues and limitations are related to the limited awareness and acceptance of the BIPV technology, which indicates behavioural and marketing aspects, not the requirement of a new technology. Hence, introducing blockchain as a way of eliminating/minimising the identified issues and limitations seems to overlook the complexity and specificity of these deeply rooted issues and limitations. While this study acknowledges that using blockchain is not the primary way of addressing the identified challenges, it promotes the ability of blockchain technology to provide effective solutions at the project level. Even though blockchain cannot resolve these issues, considering their strategic, legislative and business cultural nature, it can improve the quality of the BIPV project by providing significant project-based solutions. The study understands that finding specific solutions considering the root causes of these issues is prominent; however, having secondary measures to address them within a specific project environment by using available resources is worthy of consideration. Furthermore, blockchain facilitates a decentralised environment for information sharing and communication, enhancing project quality by integrating stakeholders and reducing information gaps and inconsistencies. Given the BIPV industry's reliance on accurate documentation, blockchain proves to be a highly beneficial technology worth introducing.

In the real world, there are simpler and less expensive technologies such as file tagging, timestamping and the use of the IPFS in distributed work environments to enhance project management. When these methods are integrated with existing enterprise resource planning (ERP) systems or well-organised Common Data Environments (CDEs), they offer reliable solutions with greater flexibility, improved coordination and better system interoperability. They also have the potential to address information-sharing and exchange challenges without introducing the additional complexity and resource demands associated with blockchain technology. While acknowledging the above opinion, this study highlights the ability of blockchain to deliver a better information management system for a temporary multiparty organisation established to complete a building project. The parties involved in a BIPV lifecycle are often unknown to each other and experience employee changes during their long lifecycle. In many cases, the designers and consultants who have been involved in the early project stage may not be available for communication in the later stages of the project due to employee turnover. Further, BIPV projects have a lot of information during their long lifespan; hence, record keeping, information tracking and the ability to access to information are vital to its maintenance. At the same time, document ownership and intellectual property rights are highly important is this line of work. This study determines that blockchain can deliver a better information-sharing system while addressing all above concerns.

Blockchain is a comparatively new technology and a hot topic in academia, especially related to improving its abilities and reducing the current issues. Hence, the current issues of blockchain will be reduced or eliminated in time. In addition, its ability to provide a decentralised environment for information sharing and communication will increase with time. For example, there are ongoing academic and industry research to identify the solutions to its high computational and power requirements. Hence, blockchain has a great potential to be applied to any industry that has multidisciplinary and multi-sector involvement, long lifecycles and highly dependent on information.

The validation is based on the findings of three semi-structured interviews with building-scale DSE stakeholders, including a project manager, PV/BIPV designer and PV/BIPV supplier. The decision to conduct only three interviews was due to the time constraints of this study and the similar feedback received from all interviewees. Since the developed BIPV information platform was adequately tested through a case study, this study assumes that the number of interviews conducted for validation is sufficient to achieve its purpose. To improve the quality of the validation process, several precautions were taken, such as selecting one expert from each main party of a BIPV project to cover the performance of all developed channels and choosing experts with more than 10 years of experience who are actively participating in PV/BIPV projects. As a result, the potential harm to the quality of this research was minimised to the best of the ability. Nevertheless, the study acknowledges that this is a significant limitation and proposes future research to address the limitation.

Future research is designed to comprehensively validate the developed platform by conducting four focus group sessions with four professional groups: (1) design team members (architects, BIPV designers, engineers), (2) construction team members (project managers, builders, developers, supervisors), (3) procurement team members (PV/BIPV suppliers, PV/BIPV manufacturers, PV/BIPV distributors) and (4) O&M team members (building managers, facilities managers, maintenance officers). Each focus group will discuss the (1) practicality of the platform, (2) benefits it can offer to the stakeholders, (3) difficulties/concerns of using the platform and (4) potential improvements and suggestions related to their profession and engagement of the BIPV project. Each focus group will comprise 5 to 7 professionals, with the aim of gathering insights from a total of 20–28 participants. The researcher will prepare a set of guiding questions to steer the discussion towards the intended research objectives. All focus group discussions will be content analysed using NVivo software to identify key themes, patterns and stakeholder perspectives.

BIPV projects have many information categories created by diverse stakeholder groups, which require circulation among the construction team. Stakeholders depend on each other for information; however, they find it difficult to maintain flawless information. In addition, BIPV projects require a higher degree of privacy to communicate supplier information. Quotations are always provided in confidence and in some cases, so are product specifications. Further, BIPV projects include many innovative and complex designs that require assuring copyright and ownership. Sharing of such documents requires a high level of security and integrity. This study developed a blockchain-enabled BIPV information management system to address all the above requirements.

The system was developed using Hyperledger Fabric backend to assure controlled access and deliver necessary transparency. It demonstrates not only the ability to share all project information via the platform, but it also indicates that sharing can be arranged only between the parties who need the information via separate channels. The separate channels for stakeholder communication were able to deliver the required protection and integrity to information. Further, the system avoids duplication of documents by providing unique document IDs and clearly labelling document revisions and editions. The developed system protects the copyright and originality of the documents via chained blocks and chronological order record-keeping and eliminates the possible exploitations which may occur in regular supply chain communication. Members cannot exploit any document without acknowledgement and third parties cannot change documents due to cryptographic and certificate-related authentication. The features of blockchain technology, such as smart contracts, consensus mechanism, DLT and digital signature, facilitated the above outcomes. The outcomes of this research will be beneficial for a number of stakeholders in the building and PV sectors and governments to encourage end-users to adopt green energy.

Theoretical contributions: The study addresses several research gaps in current research. First, there is no published information on blockchain application in BIPV projects. It is often argued that stakeholder relationships and information communication along the BIPV lifecycle have no continuous flow and are highly fragmented. Although diverse methods have been tested to avoid this unconnected nature, aspects such as improving the privacy of communication, assuring the copyright and ownership of innovative designs, securing document contents, delivering the necessary level of information transparency and avoiding information gaps are not often discussed in the current research, especially in a single study. In addition, blockchain's ability to deliver all the above aspects has been little explored in BIPV studies. This study fills the above research gap by identifying the best blockchain-enabled practices in BIPV projects and how they can eliminate (or reduce) stakeholder issues.

Practical contributions: This study will be beneficial for BIPV uptake in many ways. First, the study provides a blockchain platform prototype for BIPV information management and stakeholder collaboration. This prototype is developed considering a real case. Its design, development and operations are clearly explained. BIPV projects can use the above information to design, develop and customise their own platforms for use in real projects. Architects and design consultants of BIPV projects often face difficulties in finding product information, specifications, product standards and details of compliance with building and electrical codes. The BIPV sector also has major concerns with fire safety, structural stability and sufficient energy generation of BIPV products. Facilities managers often face the issue of not having information to compare a BIPV system's actual performance with the manufacturer's specifications. These issues occur due to limited information availability and communication gaps. The study provides blockchain-based solutions to all these issues. Therefore, this study contributes to solving most issues of diverse BIPV stakeholders.

Limitations: The prototype of the BIPV information system did not directly upload documents to the Hyperledger platform; instead, a specific link to each document was uploaded. All documents were uploaded to Cloud storage, to which only the system operator has access. storage. This generated centralised control; however, it was justified as a solution to the limited block size. In the development of the prototype BIPV information system, no system facilitator was identified; however, more control was given to the design consultancy organisation as it was the main coordinator of the actual project. However, the study could not explore the long-term O&M of the information platform by the design consultancy organisation, especially when they leave the project, due to the time constraints of the study. The limitations of blockchain technology, such as blockchain trilemma, the scalability issue, latency, transaction throughput, higher implementation and operational costs and limited block size, were not explained in the prototype development process. Further, the study did not use any expensive software applications. Therefore, these issues were not explained in relation to prototype development.

Future research directions are explained as follows:

Blockchain platform management: It is crucial to understand who the responsible party is for developing and maintaining the information management system since BIPV is a multidisciplinary project with a very long lifecycle. The facilitator's roles, duties and responsibilities should be identified in detail. The suitability of the architect, government body or an independent third party for the above role can be assessed.

Blockchain-enabled information management system for BIPV-related approvals: The suitability of using the platform to acquire required approvals can also be investigated. In such case, it is crucial to understand how the local councils and other government agencies could join the platform.