In recent years, BIM (Building Information Modeling) has been widely adopted in Architecture, Construction and Engineering (ACE) industry through design, construction, and facility management process. As most current BIM practice focusing on “the creation, collation and exchange of shared 3D models and structured data”, there is an increasing interest in both academic research and industry practice in integration of BIM and sensor technology. This research topic focuses on such integrations, and we aim to better understand the driver, enabler, current application, challenge, and potential value of BIM-sensors integration.
BIM and Sensors definition
According to BuildingSMART (2012), Building Information Modeling (BIM) is a process creating and exchanging interoperable building data along different phases of the project. Building Information Model is a digital product of such process that it contains physical and functional information of a building and supports data exchange, management and communication during the whole life cycle of a facility.
A sensor is a device to detect events or changes in its surrounding environment and feedback to the computer for further corresponding adjustment or automation. Sensors monitor real world in terms of environment (temperature, humidity, light), physical condition (pressure, vibration, and sound), occupants (motion and proximity), and convert real-time measurement into computable data. Traditionally the sensors are embedded as part of building control mechanism such as thermal control in HAVC system. Recently along with cheaper price of hardware and increasing computing power, there are increasing use in sensors connected with microcontroller (Arduino and Raspberry Pi) for academic research and product prototyping.
Integration: Where, when, and how?
Although there is a large adoption of BIM in ACE industry, BIM-sensor integration is still a large untapped research area. Based on current practice and research, we summarize BIM-sensor integrations by where, when, and how such integration occurs. There are three following typical integrations:
- Testing during design phase;
- Simulation and Monitoring building performance;
- Preventive Monitoring during construction phase;
- Facility Management during operation phase for better building performance and more robust Building Management Systems (BMS).
The physical integration of sensors with BIM depends on specific functionality of the sensor and ultimate purpose of such integration. For instance, the location of temperature sensor can be very different according to what it measures such as heat generated by mechanical equipment or indoor thermal comfort for occupants. The time length of integrations also varies by specific use cases, that sensors can be permanently installed within building system during the whole life cycle to monitor the building performance, or can be temporally integrated during the design phase for energy simulation or design testing. We will elaborate on these aspects in following ‘Use Cases’ section.
The informational integration of sensors with BIM relies on Industry Foundation Class (IFC), which serves as an international standard for semantic building models. Through IFC the sensors information can be integrated as part of building information, and sensor-generated data can be further added as live-stream data for more complex analysis. In 2013, the IFC4 version has adopted new entities regarding sensor integration. Specifically, IfcSensor indicates the occurrence of a sensor, and IfcSpatialZone define the location, shape, and function related to a specific sensor (BuildingSMART 2013).
The visual integration of sensors with BIM occurs as part of graphic user interface that the sensors are modeled as part of 3D model with their specific location. Such integration helps multiple users including architects, engineers, contractors, and building performance auditor to collaborate on a virtual environment with real-time data.
Design Testing: With increasing adoption of BIM in building design phase, researchers has been exploring the potential integration of sensors with BIM in parametric design and building automation. By combining sensor (Arduino Photo-resistor), BIM (Revit model with Dynamo) and physical mock-ups, designer can use a light sensor to drive parameters in a 3D model to change the physical configuration of the building elements (façade angel for example) (Kensek, 2014). (Figure 1)
Figure 1: Workflow of BIM-sensor integration for design testing (Kensek, 2014).
Performance Simulation and Monitoring: There is a large market in building performance especially in energy efficiency and indoor comfort monitoring. However most of previous studies on BIM have been focused on design and construction phase, and there are limited studies in integrating BIM and sensors in facility management. On the other hand, previous studies in building energy mostly focused on building control system without considering a BIM context. There is a large potential in this domain since IFC has adopted entities for energy performance including HVAC, lighting, and electrical components (Wang, 2013). There are continuing research efforts on this topic to achieve more robust energy monitoring with real-time data stream and semantic intelligence regarding the location of each sensor and program of the related building space. (Figure 2)
Figure 2: Sensor-augmented building information service for building energy management (Wang, 2013).
Preventive Monitoring: BIM-sensor integration also serves for preventive management during construction and maintenance process that it keeps track of structure condition to ensure proper condition. Sensor technology has been largely adopted in infrastructure management that there are sensors installed to monitor temperature, vibration, pressure to ensure a normal condition of certain structure. Recently there is an increasing interest in integrating such preventive monitoring system with BIM. For example, researchers in University of Cambridge, UK, has proposed BIM-sensor integration during construction phase to ensure a robust exchange of information on construction condition. In this way the building manager and auditor can track each sensor and data generated along with the 3D model of the project (Davila). (Figure 3-4)
Figure 3: Integrate sensor during construction phase (Davila, 2016).
Figure 4: Integrate sensor data and location with building model in a BIM environment (Davila, 2016).
Facility Management: BIM-sensor integration plays an important role in facility management that it connects building system with information system on a real-time basis. One aspect of such application is to create a lean version of building model (not for design or construction purpose) to connect with sensor data for building management and occupant control. Such integration enables sensor data tangible and user-friendly for property owners and occupants, which is a key component to achieve a vision in ‘smart building’ (Sensirion, 2016). (Figure 5)
Figure 5: BIM-sensor integration towards a vision in ‘Smart Building’ technology.
There are three key features in all BIM-sensor integrations we mentioned above, when integration the sensor network with building system and information system in a BIM environment.
- Semantic: BIM-sensor integration provides situational awareness for users when analyzing or managing a building system by specific location that the data associates with specific information such as the use of space, building material, equipment, occupancy, etc.
- Responsive: Such integrations enable a real-time monitoring system with live data stream, to achieve a more responsive building control system or construction management process.
- Preventive: BIM-sensor integration enable preventive management of building system and construction condition. Such integrations enable us to predict risk during the life cycle of a facility beyond real-time monitoring.
Challenges and Potentials
Although the cost of BIM-sensor integration has been decreased due to cheaper hardware and computing capability, it is still expensive to implement such integration on a large scale. One critical barrier is a lack of incentive for developers to invest, since there is a long-term monetary return. Another challenge is limited usability, that researchers and designers are still exploring a better way for users to use and interact with such information. Even regarding these challenges, we still consider there is a large value and untapped opportunity for BIM-sensor integration. Regarding the context of ‘smart city’ and large implementation of Internet of Things (IoT), there will be increasing users and devices connected on a network-based system. We expect that BIM-sensor integration will be not limited to construction control or facility management, but go beyond ACE industry and reach to other domains.
There are increasing research interest and industry practice in BIM-sensor integration for multiple purpose and project phases. Affordable hardware and computing power enable such integrations, which create value in different use cases such as design testing, building performance monitoring, preventive control, and facility management. We consider there is a large potential in this area considering the booming urban IoT and smart city applications. With better usability and interface, we expect BIM-sensor integration will go beyond typical ACE practice but also reach to everyone’s daily life.
- Davila, M. BIM Plus: Adding Value to Monitoring Data. University of Cambridge.
- Kensek, K. M. (2014). Integration of Environmental Sensors with BIM: case studies using Arduino, Dynamo, and the Revit API. Informes de la Construcción, 66(536), e044. doi:10.3989/ic.13.151
- Wang, H. G., Alex; Meissner, Stefan; Tafazolli, Rahim. (2013). Intergration of BIM and Live Sensing Information to Monitor Building Energy Performance. Paper presented at the The 30th CIB W78 International Conference, Beijing, China.
- U. Isikdag, Enhanced Building Information Models. Chapter 2: The Future of Building Information Modelling: BIM 2.0. Springer. 2015.
- Andriamamonjy, A.; Klein, R.; Saelens, D.. Sensor Handling in Building Informaiton Models. Development of a Method and Application on a Case Study. (2015) 14th Conference of International Building Performance Simulation Association, Hyderabad, India.
- Arslan, M.; Riaz, Z.; Kiani, A.; Azhar, S.; Real-time Environmental Monitoring, Visualization and Notification System for Construction H&S Management. (2014) Journal of Information Technology in Construction.