# A Review on Design Considerations and Connection Techniques in Modular Composite Construction
## 2 Conceptual Background
### Comparison of Modular Construction with Other Precast Techniques
The scoring methodology was based on detailed benchmarks from comprehensive literature and case studies [38; 39; 40; 41; 42; 43; 44]. For instance, a score of 4 was conferred to methodologies that consistently exhibited superior results across multiple studies, whereas a score of 3 denoted elevated performance with minimal restrictions or limitations. Similarly, scores of 2 and 1 were allocated based on recognised challenges or decreased efficacy in particular contexts. For example, the score of the Labour Efficiency criterion encompassed quantifiable indicators such as labour hours saved and deployment effectiveness. In contrast, the Environmental Impact was based on material wastage and energy consumption data. These methodical evaluations were designed to reduce subjectivity and provide stakeholders with an equitable comparison of the methodologies. Figure 5: Heatmap comparing (Beam and Column, Wall and Slab, and Volumetric Modular) Precast and Conventional Construction systems across key parameters. Scores (1 = Low, 4 = Very High) vary across rows based on system performance in each category. The Precast Ratio received the highest Volumetric Modular Construction (4) rating due to its prefabricated characteristics. At the same time, Beam and Column and Wall and Slab systems garnered moderate scores due to their substantial on-site assembly requirements. Conventional construction (1), characterised by minimal use of precast components, was assigned the lowest rating. Financial considerations favoured Wall and Slab and Beam and Column (2) because their reduced initial investment relative to Volumetric Modular (3) necessitated enhanced manufacturing precision and transportation logistics. Robustness was rated highest for Volumetric Modular construction (4) since its prefabricated units provide superior structural integrity when adequately connected. At the same time, other precast methodologies exhibited variability depending on their reinforcement and connection techniques. Quality Control and Labour Efficiency demonstrated that Volumetric Modular construction surpassed alternative methods, profiting from regulated factory conditions and diminished site labour requirements. In contrast, Conventional construction received the lowest score in Labour Efficiency due to its considerable demands for an on-site workforce. Environmental Impact assessments have shown that Volumetric Modular and Wall and Slab systems obtained the lowest ratings (1), indicating lesser material usage and transportation needs. Beam and Column construction earned a moderate rating (2), whereas Conventional construction displayed the most significant environmental effects (3) as a result of its higher material consumption and on-site operations. Design Flexibility, an essential element of architectural adaptability, was rated highest for Conventional construction (4), followed by Wall and Slab (3), due to their enhanced capacity for alterations. Limited by its prefabricated nature, Volumetric Modular construction obtained a moderate score (2), illustrating a compromise between efficiency and adaptability. This comparative investigation underscores each precast methodology's unique strengths and weaknesses. While Beam and Column and Wall and Slab strategies compromise efficiency and flexibility, Conventional construction retains a high degree of adaptability but lacks the advantages associated with precast integration. Among all approaches, Volumetric Modular construction stands out as the most sophisticated method, excelling in precast efficiency, labour optimisation, and structural resilience. Despite its elevated initial expenses and restricted design flexibility, its exceptional quality control, expedited construction timelines, and durability render it an optimal choice for contemporary, large-scale, and high-performance building endeavours. To further assess modular construction thoroughly, it is vital to examine this approach's myriad benefits, particularly regarding speed, cost-effectiveness, quality assurance, and environmental sustainability.