Prefabrication involves manufacturing building components in a factory and transporting them to the site for assembly. This approach improves quality through factory controls and reduces on-site construction time. Modular construction uses complete room modules or large assemblies delivered ready for connection. Prefabricated components may include wall panels, floor cassettes, roof trusses, or complete bathroom modules. Factory conditions allow quality control and consistent workmanship. Weatherproofing is ensured by construction under cover. Labor productivity is higher in factories with specialized equipment and trained workers. Repetitive work improves efficiency and reduces waste. Transportation of prefabricated components requires careful planning. Dimensions must fit on trucks and through transportation routes. Weight distribution is critical to prevent overloading. Some components require special transportation equipment. Crane capacity at the site must be adequate to lift heavy modules. Scheduling must coordinate factory production with site readiness. Site must be prepared for module placement before delivery. Connection details must be properly designed and detailed. Bolted or welded connections transfer loads between modules. Waterproofing and air sealing at connections prevent infiltration. Quality assurance in the factory catches defects before components reach the site. Defects in modular components affect many units; factory inspection is critical. Some defects cannot be corrected on-site. On-site assembly is faster than conventional construction. Coordination between assembly teams and trades prevents delays. Testing and commissioning occurs after assembly.