Should I order a pre-hung door unit or a door slab only?

A pre-hung unit arrives with the leaf, jamb, casing and hinge prep already squared and fitted — faster to install and the safer choice for new openings or renovation. A slab-only order is cheaper and works when your existing frame is sound and square. For retrofit in older buildings, slabs usually make more sense; for new construction and container projects, pre-hung reduces site labour and callbacks.