What is modular construction
Modular construction is the process of constructing building components off-site and putting together the components (also known as modular parts or modules) on-site. The modular parts could consist of numerous individual parts such as the walls, frames, doors windows and ceilings put together to create a complete modular building unit or be several prebuilt ‘complete’ modular building units put together on-site to make one large unit. The final construction should reflect the intended design and specifications achieving high build quality (Eagle 2014).
The decision to fall back on this type of construction is very often motivated by the need to meet the strict deadline for erecting buildings, as modular construction is known for high quality that can be easily reached within the shortest possible time while the result will be long-lasting and strong.
For this reason, modular construction is a common technology for building industrial plants. Nevertheless, today it is more often used for constructing business centres, telecommunications, stations, churches, educational structures, military objects, airport facilities, restaurants, and even healthcare institutions. Among the common customer using this type of construction, there are local, state, and federal governments, huge corporations and non-profit organizations, retailers and healthcare providers (The Modular Building Institute 2010). An example of where modular buildings have been used at a large scale is the B2 building in New York that was the world’s largest modular building comprising of a 32 storey residential tower where 60% of this building was constructed off-site. However, it was before the Sky City building in China that boasts a magnificent 220 storey building construction that was said to be completed in 90 days. In addition to the projects mentioned above, this practice has been used by the authorities of Hong Kong in public housing construction (Chiang et al. 2006) and Singapore (Poh & Chen 1998).
Velamati (2012) pays specific attention to the stages of modular construction detaching four specific stages. First of all, the future building is designed by the developers. At this stage, the plan is also approved by the authorities, so that it meets all the requirements regarding safety and the process of construction. At the second stage, modules are manufactured and assembled in the factory environment. Next, modular parts are transported to the assembly yards where they will later be put together. Finally, the building is constructed, and the process is over.
Advantages of modular construction
Modular buildings are becoming favourable to conventional construction, as the individual modules are carefully engineered to withstand the effects of transporting and craning them onto the foundations onsite making them structurally stronger than traditionally constructed buildings. There is also better construction quality management off-site ensuring that stringent quality control and quality assurance protocols are in place to promote an exceptionally high quality of construction in every step of the project. It is achieved through repetition, inspection and operating in a controlled factory environment, and adhering to regulations in place. All of these steps help improve performance (Court et al. 2006).
Modular parts can be built to exact specification and be replicated with the minimal error off-site usually in a factory setting thus reducing the time of completion and the need for amendments significantly. Labour reduction is also a key advantage and by using modular buildings, there is less need for supervisory personnel at the sites thereby further reducing cost and completion time. It is believed that an increased amount of personnel accounts for higher costs and longer completion times as it facilitates means for unnecessary worker interface (Proverbs, Holt & Olomolaiye 1999). In addition to it, Jameson (2007) believes that modularization helps decrease labour peaks because most work is conducted in a factory environment by the machines and with the use of assembly lines. Together with that, it is a perfect tool for reducing conflicts in the working place because the number of workers is at a minimum, so, they rarely intercommunicate and collide.
Velamati (2012) points out another desirable advantage of modular construction. The author states that it creates minimal site disruption as approximately 60-90% of the construction activity is carried out off-site in the factory environment and only the assembly, and minor work is done on-site. Moreover, it improves overall safety and security and eliminates construction hazards especially when used for erecting schools, hospitals, building dense and heavily populated areas where the safety of people and also the running of businesses are paramount. In addition to it, the author also stresses that modules in comparison with conventional construction are better insulated and more moisture tolerant, as most parts are assembled in the factory environment where weather conditions cannot affect the process and ruin the material used for building and design.
There are also advantages deriving from the strict schedule for design and construction. First of all, because of the detailed process, the delays in constructing the building are almost impossible. However, there is one crucial condition in this case – the schedule should be developed with bearing in mind possible risks and delays in transportation and assemblage. Second, strict schedule implies the strict control over the process and coordination at every stage. Third, modular buildings are usually erected faster if compared to conventional, that is why cost benefits are resulting from both savings during shorter periods of construction and income from earlier introducing into service and receiving rental payments (Ataei et al. 2015). The authors also point out that strict schedules also have a positive impact on environmental advantage. Because less time is spent on constructive, the potential negative influence on the local natural environment is reduced.
Finally, the experts from the Modular Building Institute (2010) claim that the flexible design of modular constructions makes them reusable, it means that they can later be used for erecting the building that varies from the initial design. Moreover, they can be switched during the process of assembling as one element can be used as floor, ceiling, wall or rafter. It is what makes this technique unique and to some extent universal.
Disadvantages of modular construction
Even though modular construction has many advantages, numerous significant disadvantages should take into consideration when choosing the type of construction. For example, Taghaddos et al. (2014) focus their attention on cons that might derive from short times of construction. First of all, the authors claim that because this technique is often used when the deadlines are strict, there is a need to develop a schedule that would not ignore any single minute. They stress that designing such a plan requires exquisite time management skills, and it is very often complicated to find specialists who can cope with this task. For this reason, there are sometimes delays in constructing the buildings and meeting the deadlines. Moreover, the authors pay specific attention to the limitations of this method. That said, they note that because all the modules should be ready before construction and kept in one place that is called assembly yards, there are often limits in space, as it is difficult to find the necessary surface for storage. Furthermore, the investigators stress on the necessity to involve many specialists with different skills into the modular projects. They acknowledge that hiring a worker is not a problem; what is a real challenge is to find an HR who would be able to manage them effectively. Finally, the authors believe that one more disadvantage of this type of construction is that it requires too many transporters that are first used for shipments and later for transporting the modules from one place in the assembly yard to another (Taghaddos et al. 2014).
Another disadvantage of modular construction is stated by Chiang et al. (2006) who state that the modules used in the building should correspond with particular buildability criteria determined by the state. These criteria can be used as the barrier to entry for new modules manufacturers to the market, thus leading to the emergence of monopolies in the economy. However, the authors claim that there is a way of overcoming this barrier by hiring official consultants who might help manufacturers change the production process so that the final product complies with the standards. The only problem here is that the services of the consultants are costly, that is why the price for the modules rises. What also becomes more expensive is the process of constructing a building, as it also should fall within the standards. In some cases, such new projects are more than 40% more expensive, that is why buildability criteria are another fruitful way of precluding the emergence of new companies that is, at the same time, a significant disadvantage of modular construction.
Modular construction and simulation
Taghaddos et al. (2014) believe that simulation can become an effective tool for working out the disadvantages of the modular construction, especially the constraint emerging during the process of erecting the building using the modules. According to the authors, to avoid the negative aspect of this type of building, it is necessary to assess all potential limitation that might emerge during the process such as delays in transportation, various problems deriving from the human factor, and inaccuracies in plans and schedules. The authors claim that the result of the simulation is a series of reports and graphs illustrating all the available resources. In the case of a thorough analysis of the outputs of the model, it is possible to eliminate the possibility of inaccuracies and guarantee that the deadlines are met and the plans are fulfilled.
What simulation is beneficial for is improving the scheduling of onsite installation. It is especially effective if used with visualization, claim Moghadam et al. (2012). They believe that this method helps to simplify the minute-in-minute plan for assembling and better the overall performance. The authors propose to develop three scenarios for the whole process of construction – pessimistic, optimistic, and average. It should be said that the pessimistic scenario is still acceptable because the company would still meet the deadline. The only thing that authors stress is that it is more beneficial to follow the optimistic scenario because it will help improve productivity and performance.
The use of modular construction in hospital buildings
Today, modular construction has become popular with healthcare providers, as more and more hospitals building are erected with modules. Bearing in mind that the advantages of the modular building significantly outweigh disadvantages, it is no surprise.
Ataei et al. (2015) pay specific attention to the use of modular construction in hospital buildings. The authors believe that there are several reasons for which this type of construction is more beneficial for healthcare providers than the conventional. First of all, they point out that hospital buildings are usually sophisticated and have many levels of complexity. It means that there is a need for very detailed design and, what is even more significant, bringing the initial design to life. In the case of modular construction, this objective can be easily achieved. Second, hospitals need to be sure that their buildings are safe and of high quality that can as well be guaranteed due to the strict control measures throughout the whole process of construction. Third, the demand for healthcare services continually grows. It means that the new facilities should be built within the shortest possible time. As it was shown above, using modular parts in building saves not only time but also money, that is why this type of construction is perfect for the hospitals.
Eagle (2014) states another benefit of modular for constructing a hospital in comparison with the conventional building. The author thinks over the necessity to build another building or repair some parts of the building under exploitation. What is special about modules is that they are assembled in the factory environment. It means that all the primary work is done away from patients. So, the hospitals manage to avoid dust and noise that adds not only to the comfort of patients but also to their safety. In addition to it, the author stresses that because of strict planning, it is possible to manage the resources financial as well as raw materials. It means that using this type of construction helps minimise the amount of scrap that as well improves the sustainability of a hospital because less money is spent first on buying materials, then on cleaning up the wastes.
To prove that modular construction is beneficial for healthcare institutions, Court, Pasquire and Gibb (2008) carried out an in-depth investigation of the UK hospital built with the use of modules. For this specific study, they have analysed the data regarding the overall effectiveness of conventional constructing including quality, time spent for finishing the projects, health and safety including the number of incidents in the working place and work-related illnesses, and the level of the workers’ productivity. In addition to it, the authors studied whether the use of the corridor modules is more beneficial than traditional construction. The results of the exploration were fascinating, as the authors have found out that the overall consequences were positive and could be divided into six groups: quality, time, sustainability, cost, health and safety, and site benefits. In general, erecting building using this type of technique helped save the costs and raw materials, as the number of wastes was lower than in the case of conventional construction. Second, it decreased the time for finishing the project because the workers knew that they had to meet strict deadlines and most works were finished in a factory setting, thus, resulting in achieving better quality with involving less workforce. Third, it helped improve the level of safety, as there were no accidents in the working place and the productivity of employees as they were controlled at every stage of the process.
Even though the use of modular parts for construction is, for the most part, beneficial, some barriers preclude it from becoming the widespread practice. These barriers are studied by Azhar, Lukkad and Ahmad (2012). First of all, the authors believe that this type of construction requires high-skilled workers that would work on design and planning, but they are hard to afford by the ordinary building companies. Second, not all factories have the inventory of the needed technological level that could be used for assembling the modular parts. Third, in most cases, people are unaware of the benefits of modular construction over conventional (Azhar, Lukkad & Ahmad 2012). Finally, big corporations are just used to conventional construction that is why they need some time to adapt to something new even though it is more advantageous (Carriker & Langar 2014).
Conclusion
Modular construction is not a new technique for erecting a building, and it has already gained popularity among the most varied customer from healthcare and educational institutions to non-profit organizations and governments at all levels. What first of all should be said about this technology is that minimizing the number of workers involved and maximizing the amount of work finished in a factory environment is a source of limitless benefits not only for healthcare institutions but also any other.
To sum up, the primary advantages of modular construction are minimizing the costs and maximizing the revenues that can be achieved by thorough budgeting and planning the number of necessary resources as well as finishing the construction earlier, so that there is an opportunity to receive rental payments earlier. The second advantage is improving the level of overall performance because every stage is strictly controlled and managed. Third, this type of construction is safer for the natural environment as the projects are finished sooner if compared to conventional construction. The fourth benefit is that it helps increase safety in the working place. Finally, modules are flexible in design and can be reused and recycled.
Together with that, there are as well some disadvantages of this type of erecting the buildings but they all come down to constraints whether it be a lack in time, skills or resources. Furthermore, it sometimes can be less beneficial than thought because there are buildability criteria established by the state that should be met. In the case, if the company fails to comply with them, it has to hire consultants, ad the process of reaching the determined standards is time-consuming and costly. Nevertheless, there are some disadvantages, what should be said is that they are outweighed by the advantages and can be eliminated by using simulation and visualisation while preparing the plan of the projects and developing the schedule of assembling.
References
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