Building Digital Twins

Table of Contents

1. Frontmatter

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2. Design Wire Engineer Leverage and Transfer (DWELT) Framework for Building-Level Digital Twins

   • Open Access

   Karim Farghaly, Pedro Mêda, Conor Shaw, James O’Donnell, Fulvio Re Cecconi, Nicola Moretti

   Abstract

   The adoption of Digital Twins (DTw) related technologies in the Architecture, Engineering, Construction, and Operations (AECO) sector has enhanced data-driven decision-making through bi-directional data flows and real-time analytics. However, the risk of creating new data silos and interoperability hurdles with other technologies and initiatives persist. To unlock the full potential of DTw, integration with broader digital initiatives – such as Digital Building Logbooks and Digital Product Passports – is essential. Addressing these challenges requires a System-of-Systems (SoS) approach and coordinated processes. This research explores the transition towards a SoS approach in the built environment sector. A qualitative methodology was employed, using co-creation workshop with industry professionals, software providers, and academic experts from diverse regions. The data gathered were analyzed using grounded theory, leading to the development of a scalable framework for DTw solutions. This study introduces the Define-Wire-Engineer-Leverage-Transfer (DWELT) framework, designed to support organizations in effectively implementing DTw through a SoS approach.

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3. Evaluating the Interoperability of TEASER and AixLib for Building Digital Twins Within Modelon Impact Environment: A Case Study

   • Open Access

   Laura Zabala Urrutia, Sergiu Crisan, Estíbaliz Pérez Iribarren, Iker González Pino, Jesús Febres Pascual

   Abstract

   The building sector's significant contribution to global energy consumption and greenhouse gas emissions necessitates more intelligent building design and management, leading to the growing importance of Building Digital Twins. This study focuses on functional, simulation-based digital twins that incorporate physics-based models for dynamic building performance simulation. The research investigates the interoperability of automatically generated Modelica models using TEASER (Tool for Energy Analysis and Simulation for Efficient Retrofit) and the AixLib library within the Modelon Impact simulation environment. TEASER was employed to generate reduced-order thermal building models from archetype data, which were then simulated using Modelon Impact, requiring a hybrid approach to address software compatibility issues. A comprehensive case study of a multi-level residential facility was conducted, evaluating thermal comfort and energy consumption at different levels of aggregation. The results demonstrate the feasibility of this integrated workflow for creating dynamic energy models, highlighting the trade-offs between modelling granularity and accuracy. The study contributes to more flexible and robust digital twin implementations for enhanced building performance analysis and operational decision-making.

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4. A Digital Twins Model Based on IFC Open BIM Models Managed on Web Platforms

   • Open Access

   Costantino Carlo Mastino, Juozas Vaičiūnas, Raffaello Possidente, Andrea Frattolillo, Mohsen Zavari, Valerio Da Pos

   Abstract

   The use of BIM has introduced a process of building digitalization in Europe and worldwide, including all the systems plant they contain. Italy and Lithuania, following European directives, have introduced national laws mandating the use of BIM for various projects. One of the challenges in using BIM platforms is ensuring data interoperability over the years. Currently, the only globally recognized model based on an open standard by ISO is the IFC data model. The management of buildings, with particular reference to energy and environmental aspects, is now one of the main objectives that all European Union states must pursue to ensure increasingly sustainable buildings. The use of digital models based on open BIM models could significantly contribute to the intelligent and environmentally sustainable management of buildings and systems. This work presents a case study of Digital Twins based on IFC open BIM models managed on a BIM web platform.

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5. Overview of the Use of AI in Buildings Sustainability Assessment

   • Open Access

   Turkay Ersener, Paris A. Fokaides

   Abstract

   This paper presents an overview of how Artificial Intelligence (AI) supports the sustainability assessment of buildings, structured around the main phases of the building lifecycle. The review focuses on four core stages: design and planning, operation and monitoring, assessment and optimization, and compliance and certification support. Within this structure, the study highlights the growing role of AI in enhancing decision-making, improving building performance, and supporting sustainable outcomes across each phase. AI tools are categorized into four main groups: general-purpose platforms, data analytics environments, building-specific tools, and specialized applications. These are then mapped to key application domains such as prediction, simulation, decision support, and system optimization. The study emphasizes the connection between AI functionalities and specific needs in building sustainability, offering a structured approach for understanding the current landscape of tools and methods. By combining a lifecycle-based perspective with a classification of AI technologies and use cases, the paper aims to support researchers and practitioners in navigating the evolving intersection of AI and sustainable built environments. The findings serve as a foundation for further research and tool development, fostering more effective integration of AI in future sustainability assessments.

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6. Urban Digital Twin Data Requirements and Reference Architecture for Green Spaces and Ecosystems

   • Open Access

   Lina Morkunaite, Darius Pupeikis, Vytautas Bocullo, Egle Klumbyte, Andrea Conserva, Chiara Farinea, Alice Bazzica, Peter Barmann, Fruzsina Csala

   Abstract

   As cities face growing pressure from climate change, biodiversity loss, and urbanization, there is an urgent need for data-driven tools to support the planning and resilience of green infrastructure. This paper presents a methodology for developing Urban Digital Twins (UDTs) focused on green space planning, monitoring, and regeneration. The process begins with the identification of Key Performance Indicators (KPIs) across five thematic areas: pollution and climate, natural environment, ecosystems, human perception, and public awareness. Based on these KPIs, a set of enabling digital technologies is evaluated through expert ranking, using Kendall’s W concordance coefficient to assess consensus on their relevance. The results highlight strong agreement among experts, with IoT, GIS, and BIM emerging as the most suitable technologies due to their capacity for real-time sensing, semantic integration, and spatial representation. Drawing from these insights, the paper proposes a five-layer reference architecture for UDTs designed to support adaptive, inclusive, and data-driven urban greening efforts. The findings offer guidance for cities and stakeholders aiming to implement UDTs for urban resilience.

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7. Towards True Networked Urban Digital Twins – A Development Agenda

   • Open Access

   Juho-Pekka Virtanen, Laura Mrosla, Tapani Heino

   Abstract

   Urban Digital Twins (UDT) have become ambitions for many cities globally, yet their implementation varies significantly in terms of governance, openness and their relation with external stakeholders. Currently, many UDTs still rely on manual updating, leading to discussion on whether they really are digital twins by strict definition. To maximize their utility, UDTs must be developed to meet the multiple needs of the cities (e.g. decision making) while ensuring continuous updates and adaptability. In this work, we present a development agenda for UDTs, synthesizing insights from both recent literature and the practical experiences gained through various projects carried out by Forum Virium Helsinki and the FinEst Centre for Smart Cities. In this work, we identified four key elements for the future development of UDTs: 1) establishing common understanding, 2) modularity & interoperability 3) presentation agnosticism and 4) the social dimension.

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8. Automated Planning, Execution, and Re-planning of Terrestrial Laser Scanning in the Built Environment

   • Open Access

   Thivageran Duraimany, Frédéric Bosché

   Abstract

   Terrestrial laser scanning (TLS) is commonly used for acquiring dense point clouds, used to generate high-quality 3D models, which supports Building Information Modelling (BIM) and digital twinning. However, not only is careful TLS planning necessary to ensure data completeness while minimising scanning time, but real-world conditions often introduce occlusions that prevent original scan plans from achieving the intended coverage. This study presents a method for determining optimal scanner locations through efficient discretisation of target object surfaces into key-points. In addition, it addresses the challenge of dynamically and efficiently adapting scan plans by evaluating whether new scan locations are necessary when occlusions limit visibility. This research uses 3D surface discretisation (into key-points) as the primary method for efficiently evaluating object 3D surface coverage, used during both initial scan planning and dynamic re-planning. A next-best-view algorithm is applied for overall scan plan generation. The method is validated through simulation using a model from the International Society for Photogrammetry and Remote Sensing (ISPRS) dataset, Helios++, and random insertion of clutter. This work contributes to automating TLS workflows, making them more adaptive to real-world uncertainties. Future work will focus on real-world implementation and integration with robotic scanning systems for enhanced automation.

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9. Digital Twins for Data Centre Cooling Optimisation and Waste Heat Recovery

   • Open Access

   Sara Giordani, Rossano Scoccia, Marcello Aprile

   Abstract

   The paper explores the development of a Digital Twin (DT) for the management and optimisation of heat recovery in data centres, using HYCOOL-IT project demo site. The project features the development of a “Building Digital Twin Environment” as a “Platform as a Service”, integrating SIMBOT-based interactive simulators and Web API microservices to support processes from planning to performance evaluation. The article describes the integration of a waste heat recovery system within the data centre Z3 to heat the adjacent university building BL26. The DT architecture incorporates real-time data processing and a Software-in-the-Loop Model Predictive Control system to optimise control actions. Two DTs are under development: the data centre DT and the active heat recovery system DT. The former will optimise performance by continuously monitoring and controlling data centre conditions, cooling system settings, and power supply system. Simulations of the server room, chillers, and power systems will enable testing of management strategies for use cases like free cooling and emission subsystem operation optimisation. The latter will monitor the integration of a water-water heat pump (WW-HP) with the BL26 heating system, tracking electricity use, water temperatures, and flow rates. Control strategies will adjust setpoints, operation modes, and flow or temperature differences to improve system efficiency. Dynamic simulations could assess BL26 heating demand and WW-HP. Use cases include integrating WW-HP into the current plant, optimising mid-season operation, and implementing free cooling strategies to enhance energy efficiency.

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10. Digital Twin for Datacenter: HPC4AI UniTO Case Study

    • Open Access

    Viviana Vaccaro, Robert Birke, Silvia Meschini, Lavinia Chiara Tagliabue, Sergio Rabellino, Pablo Vicente Legazpi, Marco Andinucci

    Abstract

    The HPC4AI (High-Performance Computing for Artificial Intelligence) datacenter at the University of Turin’s Computer Science Department was established to meet the rapidly growing computational demands of interdisciplinary AI research. HPC4AI innovates by redefining the traditional roles of Cloud and High-Performance Computing (HPC) systems, where the Cloud provides a modern interface for HPC, and HPC acts as an accelerator for Cloud applications. To date, it has supported over 40 research projects spanning diverse fields such as astronomy, medicine, and human sciences. Additionally, HPC4AI serves as a research and development platform for exploring, developing, and testing novel datacenter technologies. It features a variety of experimental computing platforms and the first prototype of a two-phase evaporative server cooling system. This work outlines the operational management of HPC4AI, highlighting challenges, lessons learned, and key opportunities related to digital twins for datacenters.

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11. Digital Tools for Sustainable Renovation of Heritage Buildings: From HBIM to Low-Carbon Material Selection

    • Open Access

    Erika Svytytė, Vytautas Bocullo, Lina Seduikyte

    Abstract

    This paper presents a case study on applying digital tools for the sustainable renovation of a cultural heritage building, the Mikas and Kipras Petrauskas House in Kaunas, Lithuania. The study integrates Heritage Building Information Modeling (HBIM), indoor environmental quality (IEQ) monitoring, and life cycle assessment (LCA) to evaluate renovation solutions in alignment with smart and sustainable city goals. A high-accuracy HBIM model was developed using photogrammetry and laser scanning, achieving less than 2% deviation from validated geometric dimensions. The model provided a reliable foundation for analytical workflows and demonstrated how digital capture can reduce time and mitigate reliance on outdated documentation. Indoor climate measurements indicated critical humidity conditions during the cold season, highlighting the need for improved environmental controls to preserve both occupant comfort and material preservation. LCA was employed to assess the embodied carbon of renovation materials, and alternative selections led to a 22% reduction in CO₂e emissions. The results confirm that integrating HBIM, IAQ analysis, and LCA provides a robust methodology for data-driven decision-making in heritage renovation. The approach also supports the future development of digital twin frameworks that balance environmental sustainability with cultural value.

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12. Building Digital Twin – Digitalisation of the Thermo-accumulator Used for the Building’s Heating

    • Open Access

    Tadas Zdankus, Rao Martand Singh, Lazaros Aresti, Juozas Vaiciunas, Sandeep Bandarwadkar

    Abstract

    When creating a digital twin of a building, all engineering system devices within the building must be digitised and integrated into the numerical model. This research focused on describing the processes occurring in a heat storage system, which was designed to accumulate heat during the summer period and utilise it by the building’s heating during the cold period. This is a long-term acting heat storage system with a soil-type filler. Several stages of the thermal energy storage system operation were distinguished: charging, discharging, and heat retention. During all these processes, heat exchange with the environment occurs. Typically, it is heat loss to the environment. Experimental research was performed in field conditions to analyse the mentioned processes. After each charge, the heat was dissipated in the soil volume. The output signals of the sensors were recorded and analysed. It was noticed that two temperature measurement sensors are necessary to estimate the type of work regime and charge or discharge intensity. More sensors are needed to determine the amount of stored energy more accurately.

    Creating a validated numerical model and comparing measured temperatures with simulated values at the same points enables a highly accurate assessment of the stored energy in the accumulator, as well as the description and forecast of parameter changes. By integrating the numerical model of the accumulator into the building’s digital twin and combining it with building engineering systems models, it is possible to enhance the efficiency of the building’s engineering systems and reduce energy consumption.

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13. Overview of the Use of Co-creation Tools for the Design of Sustainable Buildings

    • Open Access

    Magdalena Okrzesik, Paris A. Fokaides

    Abstract

    The transition toward sustainable building design increasingly emphasizes participatory approaches, where diverse stakeholders contribute to shaping solutions that balance environmental performance, social needs, and economic viability. This study provides an overview of the application of co-creation tools in the design process of sustainable buildings. Drawing on recent literature and practice-based examples, we examine how tools such as participatory design workshops, digital twins, virtual and augmented reality environments, and collaborative BIM platforms enable deeper engagement of users, designers, and decision-makers. The analysis identifies key benefits of co-creation, including improved user satisfaction, enhanced design adaptability, and stronger alignment with sustainability goals. It also explores challenges such as stakeholder coordination, data interoperability, and the need for capacity building in participatory methods. The study synthesizes findings across academic, professional, and policy domains to propose a typology of co-creation tools most relevant to sustainable architecture. The insights aim to inform both practitioners and researchers seeking to implement inclusive and effective design strategies in the built environment.

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14. Knowledge-Based Configuration Expert System for Deep Renovation Planning of Buildings

    • Open Access

    Joosep Viik, Ergo Pikas, Targo Kalamees

    Abstract

    Renovation is a general solution for reducing building stock emissions and energy consumption. While technical competence and digital tools exist, the renovation process is hindered by various barriers, particularly for non-expert renovation initiators (e.g., apartment building association representatives, building managers). This study proposes a knowledge-based configuration expert system (KBCES) concept as a solution to support non-experts in early-stage deep renovation planning. Using the Design Science Research (DSR) methodology, a system architecture and prototype Renokratt were developed and evaluated for typical Estonian apartment buildings.

    Renokratt was tested in a lab environment with results indicating that it can effectively support early-stage renovation planning, provided further development. The evaluation highlighted the importance of reliable building data. The study concludes that KBCES can bridge the gap between expert knowledge and end-user needs, improving the quality and pace of renovation planning while supporting broader climate goals.

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15. Evaluating the Adoption of XR Technologies for High-Risk Industrial Training Application

    • Open Access

    Caolan Plumb, Farzad Rahimian, Diptangshu Pandit, Hannah Thomas, Nigel Clark

    Abstract

    Virtual Reality (VR) is increasingly recognised as a transformative tool for safety training, particularly in high-risk fields such as construction and electrical engineering. However, to successfully integrate this technology within established training practices, training outcomes ought to be rigorously validated. By investigating the effects of eXtended Reality (XR) technology upon the delivery of safety training for high-voltage operations, this paper proposes guidelines by which instructor adoption of XR tools may be assessed and seeks to establish a methodology to measure the effectiveness of training delivery. Factors influencing instructor adoption of XR tools and methods by which staff may be prepared to integrate new training methods are discussed. An exploration of relevant performance metrics, including trainee immersion and operational accuracy, informs the design of an experiment to compare the outcomes of different training sequences: participants are allocated into four experimental groups: (1) traditional training only, (2) VR training only, (3) traditional training followed by VR, and (4) VR training followed by traditional training. Immersive Tendencies Questionnaires (ITQs) assess trainee predispositions to immersion and Presence Questionnaires (PQs) assess perceived presence within the VTE. As well as detailing the collection of data, the experiment desgin also proposes statistical analyses to determine whether VR training complements traditional methods, enhances participant confidence, and improves knowledge retention.

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16. DCU Campus Explorer: Engaging Staff and Students to Use Campus Facilities

    • Open Access

    Jaime B. Fernandez, Darragh Nagle, Annabella Stover, Fiona Earley, Kieran Mahon, Tomas E. Ward, Noel E. O’Connor, Muhammad Intizar Ali

    Abstract

    CE (Citizen engagement) is an activity that aims to provide a way to link citizens and organizations. As such it has a bidirectional channel of communication, from citizens to organization and from organization to citizens. These channels of communication should be user friendly, easily accessible and also need to fulfil other requisites depending on the use case. In that sense, CE still poses a research challenge to provide a complete solution. To this end, Digital Twin (DT) technology has been used to develop tools that integrate and visualize data of different types like 2D/3D maps digital models, sensor readings and any multimedia data. DTs have the capacity to provide as well user-friendly and easily accessible interfaces. This work focuses on the application of DT technology to DCU (Dublin City University), specifically the DCU C&C (Care & Connect) initiative that was charged with raising awareness of the services, facilities, and increasing feeling of belonging and inclusion across the DCU campuses. Services such as sexual health services, wellness support, and facilities like quiet rooms, sensory pods, and room locations. The use of DT technology has enabled the development of a live Campus Explorer with which students can interact in a user-friendly and easily accessible manner on a web-based interface using mobile phones, tablets or laptops. This paper provides an overview of the DCU Campus Explorer and how it is being used in practice by 22,000 students, more than 3,000 staff plus visitors at https://www.dcu.ie/CampusExplorer.

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17. Backmatter

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