The challenges of adopting and implementing lean construction (LC) have led to substantial but isolated research studies concerning the relevant barriers, enablers, and implications, which lack a ...comprehensive approach and analytical as well as conceptual perspectives. Hence, this study aims to fill the mentioned knowledge gap by identifying the barriers, enablers, and implications of implementing lean construction and exploring their relatedness. A systematic literature review was carried out through which 230 located studies were analyzed using thematic and content analysis methods to realize the objectives of this study. The findings suggest that the lack of awareness and understanding of LC, resistance to change, and a lack of support and commitment from top management are the top three barriers toward LC adoption and implementation, which can be overcome using the identified enablers, among which the top three ones were developing lean culture, application of lean principles tools and techniques, and top management support and commitment. Moreover, the results present a model which portrays the relatedness between the discovered barriers, enablers, and implications of applying lean construction. The findings can be insightful for the research community and project practitioners in their efforts for facilitating the adoption and implementation of lean construction.
The shortage of constructive philosophies, principles, techniques, and tools in construction project delivery and sustainability before the 1990s, together with the abundance of them after 2000, ...creates two different eras which are of prime importance. The former one’s considerable advantage was a common understanding and set of practices (e.g., the critical path method for scheduling), which seems to be a goal to achieve in the later one. In this regard, the combination and integration of best practices, tools, and techniques in construction project delivery can be considerably helpful for benefiting from their advantages and covering their limitations. Thus, this study aims to develop a conceptual framework for lean and sustainable project delivery in building construction projects. To do so, a systematic literature review was carried out, through which 230 studies were located and analyzed via thematic analysis to realize the purpose of this study. The findings present a conceptual framework for project delivery which combines and integrates sustainability, lean construction, and building information modeling in terms of principles, practices, tools, and techniques. Practically, this study’s results inform practitioners in the construction industry on the lean and sustainable delivery of building construction projects.
Collaborative models and working practices have considerably contributed to the evolution of construction project delivery in the last four decades. The promising performance results of construction ...projects with collaborative delivery models are mostly attributed to their behavioral elements (e.g., mutual trust), which have been frequently mentioned in the literature. However, the interrelationships between these behavioral elements as well as the enablers of these behavioral elements are two knowledge gaps which need to be addressed. Therefore, this study aims to fill the mentioned knowledge gaps by addressing the behavioral elements of collaborative project delivery models from analytical and conceptual perspectives. To do so, a systematic literature review was undertaken by locating 201 relevant studies and reviewing them. This was followed by the thematic analysis of the obtained research data and the development of a model for meeting this study’s objectives. The findings present a model, illustrating the behavioral elements of collaborative delivery models in construction projects, their interrelationships, as well as their enablers. The model reveals that the establishment of equality and mutual respect between project team members is a fundamental step toward mutual trust and open communication. These findings can be insightful for the research community and project professionals interested in collaborative construction project delivery.
We estimated the hourly probability of airborne severe acute respiratory coronavirus 2 (SARS-CoV-2) transmission and further the estimated number of persons at transmission risk in a day care centre ...by calculating the inhaled dose for airborne pathogens based on their concentration, exposure time and activity. Information about the occupancy and activity of the rooms was collected from day care centre personnel and building characteristics were obtained from the design values. The generation rate of pathogens was calculated as a product of viral load of the respiratory fluids and the emission of the exhaled airborne particles, considering the prevalence of the disease and the activity of the individuals. A well-mixed model was used in the estimation of the concentration of pathogens in the air. The Wells-Riley model was used for infection probability. The approach presented in this study was utilised in the identification of hot spots and critical events in the day care centre. Large variation in the infection probabilities and estimated number of persons at transmission risk was observed when modelling a normal day at the centre. The estimated hourly infection probabilities between the worst hour in the worst room and the best hour in the best room varied in the ratio of 100:1. Similarly, the number of persons at transmission risk between the worst and best cases varied in the ratio 1000:1. Although there are uncertainties in the input values affecting the absolute risk estimates the model proved to be useful in ranking and identifying the hot spots and events in the building and implementing effective control measures.
•A relatively simple but scientifically sound model for transmission of airborne infectious pathogens is presented.•This model has been applied to a real-life building and activities in a day care centre for the transmission of SARS-CoV-2.•Significant differences in infection probabilities and number of persons at risk between spaces and events were revealed.•Ranking of high-risk rooms and activities enables an efficient focus on the risk mitigation measures.
The phenomenon of waste in the construction industry has received considerable attention from the project professionals since the emergence of lean construction. In the research community, however, ...identifying causes of waste together with waste detection and elimination in the context of construction have been addressed in a limited manner. Moreover, there are very few studies, if any, which have tried to revisit the concept of waste ontologically and to look into the causes of waste through the lens of their relation to other elements in construction projects such as delivery elements and lifecycle phases. Therefore, this study aims to fill this knowledge gap through developing a novel conceptualization of waste and exploring causes of waste in construction projects to reveal their connection to various project attributes. To do so, a systematic literature study was conducted through which relevant studies were located and analysed to achieve the purposes of this study. The findings propose a novel conceptualization of waste and value based on their overlooked components. Moreover, the results present a model which reveals the connection between the identified causes of waste and project attributes (life cycle phases, relevant party, project delivery element, and waste categories in general). The obtained results can be insightful for project practitioners and the research community to reach in-depth understanding of the waste concept.
Purpose
The construction industry has considerably evolved in the recent two decades due to the emergence of sustainability, lean construction (LC) and building information modelling (BIM). Despite ...previous research efforts, there is still a gap concerning the multidimensional nature of their integration. Hence, this study aims to fill the mentioned knowledge gap through exploring and comparing the challenges, enablers, techniques as well as benefits of integrating LC with BIM and sustainability in building construction projects.
Design/methodology/approach
A systematic literature review was conducted to fulfill the purpose of this study.
Findings
The findings reveal and compare the challenges, enablers, techniques and benefits of integrating LC with BIM and sustainability in building construction projects. The results suggest that there are eight common challenges for integrating LC with BIM and sustainability, including high initial cost, lack of collaboration, lack of professionals and lack of compatible contractual framework. The discovered challenges, enablers, techniques and benefits seem to be mostly routed in people. The findings also suggest that the synergistic benefits of integrating LC with BIM and sustainability can overcome the common challenges (safety, reliability, productivity, collaboration and quality) in construction projects.
Originality/value
The findings contribute to the literature and practice concerning the integration of LC with BIM and sustainability by exploring, comparing and discussing the relevant challenges, enablers, techniques as well as benefits. Moreover, the findings reveal the significance of the development of people in construction industry, besides processes and technology, as people are always subject of activities in construction while processes and technology are always objects.
The significant share of buildings from total energy consumption across the world has been mentioned and emphasized very well by several scholars. In this regard, there have been major developments ...and improvements in the expertise of developing and designing buildings to be adequately energy efficient. However, the recent studies show that there is still a considerable deviation between the intended and actual energy consumption of the completed buildings. Hence, this exploratory study aims to discover the origin of success and failure in achieving energy efficiency in building construction projects with a life cycle perspective and based on viewpoints of key participants in the project and constructed building's operation. To do so, 21 semi-structured interviews were conducted with Finnish project professionals representing client, design/planning experts, contractors and building operation/maintenance experts. Both thematic analysis and content analysis methods were employed for analysing the obtained research data. The findings reveal a set of challenges/barriers and solutions/enablers which account for failure and success of achieving energy-efficient buildings. The obtained results contribute to the existing body of knowledge and practices on achieving energy efficiency in building construction projects.
•Higher fluctuation of occupancy rate and average was 0.55 during office hours.•IAQ is fallen to Category I but overheating problem was found during both seasons.•DCV system saved 7–8% of primary ...energy compared to CAV system.•Water priority cooling system, ‘Ref.EA.WP Case’, gave better thermal performance.•Ref.EA.WP used 0.6–1.0% higher primary energy compare to Ref.EA.24 and Ref.EA.GC.
Indoor climate and energy performance of Finnish low energy office building were studied to determine optimal control and operation solutions of demand controlled room conditioning and ventilation system with airflow rate controlled active chilled beams. Onsite measured temperature, CO2, occupancy rate were used to calibrate a dynamic simulations model. The results showed an average occupancy rate of 0.55 during office hours (OH) offering a good energy saving potential for demand control ventilation (DCV) system. DCV system used 7–8% less total primary energy compared to constant air volume (CAV) system depending on control and operation strategy used. DCV system saving was 33–41% if only heating, cooling, fans and pumps primary energy were considered. Supply air temperature controlled according to extract air temperature instead of outdoor air temperature minimized overheating problem which occurred with design solution during both seasons and systems. DCV system with active chilled beam complied at least 94% and 90% of OH with Category II indoor climate with water priority cooling and air priority cooling control respectively. Ceiling cooling panel showed an effect of decoupling cooling from ventilation resulted only in 0.9% additional primary energy saving compared to DCV system with active chilled beams.
The aim of this study was to assess the effectiveness of air cleaning in reducing the risk of respiratory infection in two day care centres using a simple and robust calculation model. Additionally, ...we aimed to identify potential hotspots for infections in indoor setting and focus countermeasures accordingly. Initial results from an interventional clinical study are provided as proof-of-concept for the model. We constructed a mathematical model to assess the number of persons at risk for airborne infection transmission in day care. Utilizing the model, we used portable air cleaners in two day care units (A and B, number of children participating in the study n = 43) and compared infection incidents between the two intervention units to the rest of the units in city of Helsinki (n = 607). The intervention buildings had mechanical supply and exhaust air ventilation. The risk modelling suggests that the use of air cleaners reduced the expected number of persons at infection transmission risk significantly. At day care centre A the average reduction was 60% (range 52% - 88%) and at day care centre B 53% (range 14% - 59%). During the approximately six month study period, we observed a significant difference in the days absent from day care due to infections between the intervention and reference day care units. On average, the parents were absent from work due to child’s illness in reference day care centers for 5.53 days and 3.77 days in intervention day care centers during the study period (p=0.009). In relative terms the reduction was approximately 32%. Our study offers compelling evidence to support increasing non-infectious air flow rates in daycare centers during periods requiring infection risk management. This can be implemented with portable air cleaners as an effective and cost-efficient strategy for mitigating the spread of respiratory infections among children. The clinical results support the findings suggested by the theoretical model.
–Air cleaning seems to be an effective way to reduce infection risk in day cares–Identification of infection risk hotspot will help in desgining the preventive methods–Portable air cleaners offer an affordable and versatile solution also in buildings where existing ventilation is insufficient for infection risk management”
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