People use to think that prefab was faster and it might have been at one time but now with all the air tools on the job now a days its must faster and better to build on site but you must have good subs .
Pre-fab comes in so many shapes and sizes. Even multi-story buildings have components that are pre-assembled in panel shops, delivered to the jobsite on flatbeds and hoisted into place with a crane. Prefabrication allows for a certain level of quality control and speed that may not always be available to a project site. It also allows for quick delivery and installed on a site with little or no staging/storage area available.