## 3 Search Results and Classification
### Construction Costs  
In 41 studies, qualitative or quantitative aspects were reported or statements were made regarding the cost variations associated with the use, application, or implementation of industrialized construction systems. Figure 3 shows the data reported by the authors,  
Figure 2: Number of publications by year and country. where the reduction and percentage increase in costs were grouped. In thirty-eight studies, a reduction in costs was reported when using industrialized construction systems, and in three, the opposite was reported. Only 13 studies provided quantitative data on costs related to the manufacturing stage. Specifically, studies M6, M7, M10, M12, M13, P22, P30, P40, P55, P57, P63, and P65 reported cost reduction values, while, on the contrary, study P56 reported an increase in costs. All these studies originate from different countries, such as Malaysia, New Zealand, China, Chile, Italy, Portugal, Norway, the United States, and India, among others, which shows that the adoption of these techniques is widespread but, at times, underexplored. Additionally, 80% of the studies are associated with prefabricated systems and 20% with modular systems. The figure shows a trend towards cost reduction, ranging from 7% to 50% using prefabricated, modular construction, or additive manufacturing techniques (3D printing). It is important to note that most of the studies analyzed prototypes of housing, construction systems, or working methodologies and did not necessarily calculate the costs of full-scale projects. Studies P22, P57, and P65 (prefabricated) reported the highest cost reductions, 30%, 30%, and 50%, respectively. These indicators are similar, which is interesting considering that these results come from different geographic and economic contexts. The countries where these results were reported are Italy, Spain, and India, respectively. In this same category, study P56 reported the opposite, considering an increase in costs, with a variation range from 26% to 72%, attributed to the lack of experience in high-rise building construction using prefabricated wooden systems. This comparison was specifically made for a case study of eight buildings in China, where traditional reinforced concrete methods have predominantly been used for such structures. This comparison was specifically made for a case study of eight buildings from the African continent, where modern techniques have not been widely explored, and instead, traditional reinforced concrete methods have been used for this type of construction. Studies M2, M10, M11, M12, P12, P15, P18, P22, P30, P31, P32, P40, P43, P54, P55, P57, P63, P65, P68, P70, P71, P72, and P74 indicated that the implementation of industrialized construction makes projects more profitable and efficient compared to traditional construc  
Figure 3: Cost variation of industrialized projects/solutions with respect to traditional projects/solutions. tion. The new methods allow significant savings in materials and energy, as well as greater efficiency in construction times. The use of advanced technologies, such as 3D printing and just-in-time (JIT) methodology, contributes to reducing operational and installation costs. Additionally, prefabrication promotes the reuse and recycling of materials, which also helps reduce production costs and, in the long term, ensures lower operating costs. In studies M7, P17, and P67, ideas regarding the reduction of material consumption and waste generation were unified, which translates into a lower total project cost. Moreover, these methods allow for a reduction in the use of energy and raw materials, contributing to more sustainable construction. Studies M12, M13, P16, P29, P69, and P73 reported improvements in terms of efficiency and productivity in the construction industry. The implementation of emerging technologies, such as the Internet of Things (IoT) and optimization algorithms, allows for better project management, ensuring quick deliveries, reducing errors, and minimizing rework.