# Special Issue Cognitive Buildings
## 9 IoT Open-Source Architecture for the Maintenance of Building Facilities  
[PERSON] et al. [8] debate about the introduction of the Internet of Things (IoT) in the construction industry, which is evolving Facility Maintenance (FM) towards predictive maintenance development. The predictive maintenance of building facilities requires continuously updated data on construction components to be acquired through integrated sensors. The main challenges in developing predictive maintenance tools for building facilities is IoT integration, IoT data visualization on the building 3D model, and the implementation of a maintenance management system on the IoT and Building Information Modeling (BIM). The current 3D building models do not fully interact with IoT building facilities data. Data integration in BIM is challenging. The research aims to integrate IoT alert systems with BIM models to monitor building facilities during the operational phase and to visualize building facilities' conditions virtually. To provide efficient maintenance servicesfor building facilities, this research proposes an integration of a digital framework based on IoT and BIM platforms. Sensors applied in the building systems and IoT technology on a cloud platform with open source tools and standards enable the monitoring of a real-time operation and the detection of different kinds of faults in the case of malfunction or failure, therefore sending alerts to facility managers and operators. The proposed preventive maintenance methodology applied on a proof-of-concept Heating, Ventilation, and Air Conditioning (HVAC) plant adopts open source IoT sensor networks. The results show that the integrated IoT and BIM dashboard framework and implemented building structures preventive maintenance methodology are applicable and promising. The automated system architecture of building facilities is intended to provide a reliable and practical tool for real-time data acquisition. An analysis and 3D visualization to support the intelligent monitoring of the indoor condition in buildings will enable the facility managers to make faster and better decisions and to improve building facilities' real time monitoring with fallouts on the maintenance timeliness.  
BIM-Based Research Framework for Sustainable Building Projects: A Strategy for Mitigating BIM Implementation Barriers  
[PERSON] et al. [9] underline that although Building Information Modeling (BIM) can enhance the efficiency of sustainable building projects, its adoption is still plagued with barriers. In order to incorporate BIM more efficiently, it is important to consider and mitigate these barriers. The aim of this study is to explore and develop strategies to alleviate barriers in developing countries, such as Malaysia, in order to broaden the implementation of BIM with the aid of quantitative and qualitative approaches. To achieve this aim, a comprehensive literature review was carried out to identify the barriers, and a questionnaire survey was conducted with construction projects' stakeholders. The ranking analysis results revealed the top five critical barriers to be the \"unavailability of standards and guidelines\", \"lack of BIM training\", \"lack of expertise\", \"high cost\", and \"lack of research and BIM implementation\". Comparative study findings showed that the \"lack of research and BIM implementation\" is the least important barrier in other countries, such as China, United Kingdom, Nigeria, and Pakistan. Furthermore, a qualitative analysis revealed the strategies to mitigate the BIM implementation barriers to enhance sustainable goals. The final outcome of this study is the establishment of a framework incorporated with BIM implementation barriers and strategies, namely, the \"BIM-based research framework\", which can assist project managers and policymakers towards effective sustainable construction.