Over the last few decades, energy efficiency has received increasing attention from the Architecture, Engineering, Construction and Operation (AECO) industry. Digital Twins have the potential to advance the Operation and Maintenance (O&M) phase in different application fields. With the increasing industry interest, there is a need to review the current status of research developments in Digital Twins for building energy efficiency. This paper aims to provide a comprehensive review of the applications of digital twins for building energy efficiency, analyze research trends and identify research gaps and potential future research directions. In this review, Sustainability and Energy and Buildings are among the most frequently cited sources of publications. Literature reviewed was classified into four different topics: topic 1. Optimization design; topic 2. Occupants’ comfort; topic 3. Building operation and maintenance; and topic 4. Energy consumption simulation.

End users’ maintenance requests gathered from computerized maintenance management systems (CMMS) configure a rich source of information to evaluate the occupants’ satisfaction and the building systems. Nevertheless, the non-standardized data gathered from CMMS makes it difficult to carry out analytics. This paper presents a text mining approach to extract information from end users’ maintenance requests and an analysis of 6,830 maintenance requests derived from 46 buildings including offices, academic buildings and laboratories over two and a half years. The research results reveal that the most common maintenance requests during building operation and maintenance are related to problems in electrical and HVAC fixtures. Although the year of construction is not related to the occupants’ maintenance requests, the type of building use and building property do influence them. The implementation of control and preventive strategies based on these results may increase facility managers’ productivity and building systems’ performance.

The technical performance assessment of a building is essential for planning maintenance actions to improve its condition and functionality. The aim of this study is to present a building inspection system for evaluating the technical performance of existing buildings, considering the importance of the entire building and the interdependence of its parts. A questionnaire survey to identify the main defects that affect the technical performance of a building was administered. The system was then validated on a university campus that houses 22 buildings. The results revealed three main applications of the proposed system: a comprehensive asset analysis, a building operation analysis, and a risk analysis system.

It is vital to select the right project bidders, as this affects the success of a project. Although there are numerous methods for assessing bidders, communication is rarely taken into account. This paper discusses the results of a survey on communication key performance indicators (KPIs) and the success of construction projects. Data were collected from 390 construction partners in Spain. The results indicate that the most significant communication KPI is the quality of information: basically, its accuracy and timeliness. In addition, experienced respondents placed less importance on communication flow structures and communication management than did inexperienced respondents. Experienced respondents distrusted new trends and/or management theories and mainly relied on experience. The findings also reveal that the communication flow structure, the communication and information management plan, and the channels of communication are relevant aspects for the success of a project. The results of this research can be used to assess bidders’ communication abilities and systems.

Post-occupancy evaluations are common tools used to periodically assess Indoor Environmental Quality (IEQ) in tertiary buildings. Although the large amount of data collected from surveys contain valuable information, the influence of building characteristics on IEQ considering the different uses of the rooms and different types of occupants is rarely considered in the evaluation. This study presents an analysis of the association between building characteristics and IEQ in different building rooms (classrooms and offices) and different occupants (students and lecturers) using a post occupancy evaluation survey to 1013 occupants in 26 higher educational buildings in Spain under a Mediterranean climate. This research demonstrated that building characteristics influence IEQ perceptions of the different rooms in tertiary education buildings. The possibility of controlling the lighting, shadows or heating, ventilation air or conditioning (HVAC) systems are the most influential factors when analyzing IEQ. The findings of this research are of interest to facility managers aiming at implementing energy efficiency measures based on user-centric satisfaction or developing maintenance plans focused on IEQ enhancement.