A digital twin can be accurate on the day it is created and wrong six months later.
A control sequence changes. A pump is replaced. A sensor is moved. Occupancy schedules shift. A renovation changes the spaces served by an air-handling unit. The building continues to evolve, while its BIM model, documentation and analytical models may continue describing an earlier version of reality.
- Control change
- Pump replaced
- Sensor moved
- Renovation
Every unrecorded change widens the distance between what the building is and what its model says it is.
This creates a fundamental problem.
A digital twin should represent the physical building. If the building changes but the twin does not, the connection gradually breaks.
Research on operational building digital twins repeatedly identifies this challenge. Fragmented workflows, incomplete operational data, interoperability problems and information loss between design, commissioning and operation make it difficult to keep physical buildings and their digital representations synchronized.12413
The difficult part of a digital twin is therefore not creating it once.
It is keeping it alive.
The problem
Buildings are not static assets. During decades of operation, equipment is replaced, control parameters are adjusted, spaces change use, sensors fail, maintenance interventions alter system behavior, and operating schedules evolve.
The information describing the building changes at different speeds.
Each source can be correct within its own context while describing a different state of the building.
Consider a simple example.
The original model says
AHU-03 → serves Zone B
Five years later, after a renovation
AHU-03 → serves part of Zone B
AHU-05 → serves the rest of Zone B
The physical building has changed. If the relationship in the digital representation remains unchanged, analytics built on top of it may now reason from incorrect information.
This is where a digital model and a continuous digital twin begin to diverge.
What is a continuous digital twin?
A digital model is not automatically a digital twin. BIM provides valuable information about spaces, systems, equipment and geometry. But BIM alone does not necessarily know what is happening inside the building today.
Operational digital twins add another requirement: ongoing connection between the physical asset and its digital representation. Research describes building digital twins as virtual representations combining relatively static building information with dynamic operational data, enabling monitoring, analysis, prediction and, in some implementations, feedback control.2312
The distinction matters.
Room 204 design temperature = 21°C
Room 204 current temperature = 25.8°C
Room 204 current temperature = 25.8°C → abnormal relative to expected operation → associated with AHU-03 → behavior changed after maintenance intervention
Each step adds context, not just data.
The value is not simply receiving live data.
It is maintaining the relationship between the data and the evolving physical building.
What has to stay synchronized?
Keeping a digital twin alive involves several different kinds of information.
01 · Physical structure
Rooms, zones, equipment, circuits and system topology describe how the building is physically organized. Renovations and equipment replacements can change these relationships.
02 · Operational state
BMS, IoT and meter data describe what the building is doing now. Research demonstrations have connected BIM with BMS and IoT platforms using APIs, WebSockets, LoRaWAN, Node-RED and other integration architectures for operational monitoring and analysis.28
03 · Semantic meaning
A sensor identifier such as TE204_01 has little value unless the system knows what it measures, where it is located, what equipment it relates to and which unit it uses. This remains difficult because BIM, BMS, IoT platforms and other systems frequently use different schemas, naming conventions and semantic representations.45
04 · Operational behavior
Even when the physical configuration remains unchanged, behavior can change. Occupancy may shift. Control parameters may be modified. Equipment performance may deteriorate.
A useful twin therefore needs to represent not only what the building contains, but how normal operation changes over time.
The synchronization loop
A continuous digital twin can be understood as a loop rather than a finished model.
- Building
- Observations
- Comparison
- Discrepancy
- Interpretation
- Model update
↺ back to the building, continuously
The physical building generates evidence through sensors, meters, automation systems, maintenance events and documents. The digital representation establishes what should exist and, where models are available, how it should behave. The two can then be compared.
If they agree, the twin gains evidence that its representation remains plausible. If they disagree, something deserves investigation. That discrepancy might indicate:
Research has demonstrated this principle using learned expectations and residuals. Building models can estimate expected measurements and compare them with observed values to detect anomalous deviations. Other approaches use virtual sensors or classifiers to identify faulty measurements.79
The important point is that disagreement should not automatically mean the building is faulty.
Sometimes the model is wrong.
AI can help the twin question itself
Traditional digital twins depend heavily on manual engineering.
At portfolio scale, that becomes expensive. AI creates opportunities to automate parts of this maintenance process.
Research on building metadata inference identifies tasks including equipment-type classification, relationship inference and extraction of operational information from time-series data. Other work has used machine learning and domain knowledge to convert physical observations into semantic building representations.67
Instead of assuming
VAV_214 belongs to AHU-03
a system could combine
→ and determine whether the relationship remains plausible.
AI therefore has a potentially more important role than simply predicting energy consumption.
It can help maintain the building's digital context.
Documents are part of the feedback loop
Not every building change appears in sensor data.
Much of this information remains unstructured. Recent research has applied NLP, computer vision, OCR, large language models and multimodal methods to engineering documents, drawings and BIM-related information extraction. Demonstrations include extracting structured information from technical reports, mapping textual requirements to BIM elements, and converting mixed text, images and tables into provenance-linked information.
That changes how a continuous twin can be maintained. Instead of requiring every building modification to be manually entered into one master database, AI can help detect evidence of change across the information already produced during normal building operation.
But extracted information should not silently overwrite existing knowledge.
A contradiction is evidence.
When the model and reality disagree
Imagine that the twin contains a record for one pump, and new evidence arrives from two directions.
Previous state
Pump P-12 → installed 2018 → nominal power 4 kW
Source: original equipment record
Evidence of change
- Maintenance report:
P-12 replaced with 3 kW variable-speed pump - Electrical measurements: a corresponding change in operating behavior
Current state
Pump P-12 → 3 kW variable-speed
Source: maintenance report + measured behavior, linked to the previous state
Three pieces of evidence now point toward a change in the physical building. A robust continuous twin should not simply erase the old information. It should represent previous state → evidence of change → current state, with provenance attached to both.
This is especially important because automated discrepancy detection is not perfect. Studies demonstrate that model-versus-measurement comparisons can identify abnormal behavior, but current evidence does not show that algorithms can reliably determine the cause of every discrepancy across arbitrary buildings.79
Human verification therefore remains important. The goal is not to eliminate engineering judgment.
It is to direct that judgment toward the changes that actually require attention.
The models themselves can become outdated
There is another problem. Even if the building information remains correct, an AI model trained on historical operation can become stale.
Suppose an energy model learns the relationship between outdoor temperature, occupancy and heating demand. Then the building receives new windows. Or its ventilation schedules change. Or occupancy patterns shift permanently. The statistical relationship learned from historical data may no longer represent the building.
This is a form of model drift.
Research has demonstrated online updating of building models and controllers using new operational observations. Some studies have continuously adjusted model parameters based on prediction error or updated controllers during real building operation.1011 However, the evidence for fully automated concept-drift detection and continual learning in operational buildings remains limited.
Maintenance 1
Building representation
kept synchronized with the physical asset
Maintenance 2
Analytical models
kept synchronized with changing behavior
Continuous twins require both. Ignoring either one eventually makes the twin less trustworthy.
Why keeping the twin alive matters
The purpose of synchronization is not to create a technically impressive model. It is to improve operational decisions.
A current digital twin can give fault detection more context. An abnormal temperature can be linked to the equipment capable of causing it. Unexpected energy consumption can be compared with system configuration and operating schedules. Maintenance teams can investigate whether behavior changed after an intervention. Predictive models can be recalibrated when the underlying building changes.
Research already reports applications of AI-enabled digital twins in energy optimization, HVAC control, fault detection and predictive operation. Some individual demonstrations report substantial improvements, although methodologies and building types differ considerably and results should not be generalized across portfolios.12
A digital twin becomes operationally valuable when its representation remains trustworthy enough to support these decisions.
Industry perspective
Continuous monitoring, model calibration and AI-assisted integration have each been demonstrated. Current research still identifies interoperability, incomplete data, uncertain data quality, legacy infrastructure, standardization, scalability, cybersecurity, implementation cost and organizational readiness as important barriers.341314
Most importantly, many published demonstrations remain individual buildings, specific systems or relatively controlled implementations.
What the evidence does not yet support
Not yet established
- Fully autonomous synchronization of arbitrary existing buildings.
- Reliable automatic identification of every physical or operational change.
- Universal semantic mapping across legacy BIM, BMS, IoT and maintenance systems.
- Robust continual learning across heterogeneous building portfolios without engineering supervision.
- Autonomous AI operation of buildings without human oversight.
Continuous digital twins are becoming technically feasible.
Fully autonomous digital twins are not yet an established building-industry capability.
How Struxiva applies these principles
At Struxiva, we approach the digital twin as something that must evolve with the building. The starting point is connected building knowledge.
The next step is maintaining consistency between them.
The objective is not a digital model that is periodically rebuilt.
It is a building representation capable of showing where its understanding of reality may have become outdated.
Key takeaways
- Buildings continuously change, so a digital twin created once will gradually lose alignment with the physical asset unless it is maintained.
- Continuous digital twins combine relatively static building knowledge with changing operational evidence from BMS, IoT, meters, maintenance and documents.
- AI can help automate metadata inference, document extraction, anomaly detection and parts of model updating.
- A discrepancy between measurements and the twin does not necessarily mean the building is faulty. The digital model itself may be outdated.
- Analytical models can also become stale as equipment, controls and occupancy change.
- Current research supports specific implementations of continuous monitoring, model calibration and AI-assisted integration, but not fully autonomous synchronization across arbitrary building portfolios.
- The long-term value of a digital twin depends less on how detailed it is when created than on whether it can remain trustworthy as the building changes.
Evidence & references
Digital-twin lifecycle, integration and interoperability
- Raitviir, C., & Lill, I. (2024). Building digital-twin lifecycle and information-integration research. Buildings, 14, 2207. doi.org/10.3390/buildings14072207
- Hauer, M., et al. (2024). Building digital-twin and operational-data integration. Buildings, 14, 805. doi.org/10.3390/buildings14030805
- Mousavi, Y., et al. (2024). Digital-twin integration and challenges in smart cities and buildings. Smart Cities, 7. doi.org/10.3390/smartcities7050101
- Omrany, H., et al. (2023). Digital-twin interoperability and data challenges. Sustainability, 15, 10908. doi.org/10.3390/su151410908
- Lei, B., et al. (2023). Digital-twin interoperability and information integration. Automation in Construction. doi.org/10.1016/j.autcon.2022.104716
Semantic twins, metadata inference and model calibration
- Benfer, R., & Müller, J. (2024). AI-supported semantic digital twins, including metadata inference, classification and relationship extraction. Energy and Buildings. doi.org/10.1016/j.enbuild.2024.114637
- Bjørnskov, J., et al. (2025). Ontology-driven automated generation and calibration of data-driven building models. Applied Energy. doi.org/10.1016/j.apenergy.2025.125597
- Biagini, C., et al. (2024). BIM, IoT and BMS integration in operational buildings. Journal of Information Technology in Construction. doi.org/10.36680/j.itcon.2024.049
- Darvishi, H., et al. (2023). Virtual-sensor and machine-learning approaches for real-time sensor fault detection. IEEE Sensors Journal. doi.org/10.1109/JSEN.2022.3227713
Online learning and AI-enabled operation
- Stoffel, P., et al. (2024). Online learning and adaptive building control under real operating conditions. Energy and Buildings. doi.org/10.1016/j.enbuild.2024.113895
- Sha, X., et al. (2025). Online adaptation of data-driven building models for predictive control. Applied Energy. doi.org/10.1016/j.apenergy.2025.125341
- Wong, R. W. M., & Loo, B. P. Y. (2025). AI-enabled digital-twin applications for building energy operation. Journal of Building Engineering. doi.org/10.1016/j.jobe.2025.113966
Implementation challenges
- Ghansah, F. (2024). Digital-twin implementation challenges in facility management. doi.org/10.1108/SASBE-10-2023-0298
- Arsecularatne, B., et al. (2024). Challenges and limitations of digital twins in the built environment. Sustainability, 16, 9275. doi.org/10.3390/su16219275
A building model becomes a digital twin by connecting it to reality. It remains a useful digital twin only if that connection survives change. The next generation of building intelligence will therefore not be defined simply by better models. It will depend on systems capable of detecting when their representation of the building is becoming outdated, finding the evidence that explains why, and keeping human operators in control of what changes.
In the next article, we'll look at building data quality: why every AI claim about a building inherits the quality of the records underneath it.
Ready to see this in practice?
Talk to us about building intelligence that stays connected to the building as it changes.