Anastylosis
Anastylosis (from the Ancient Greek: αναστήλωσις, -εως; ανα, ana = "again", and στηλόω = "to erect (a stela or building)") is an archaeological term for a reconstruction technique whereby a ruined building or monument is restored using the original architectural elements to the greatest degree possible. It is also sometimes used to refer to a similar technique for restoring broken pottery and other small objects.
Methodology
The intent of anastylosis is to rebuild, from as much of the original materials that is left after usually thousands of years of abuse, historical architectural monuments which have fallen into ruin. This is done by placing components back into their original positions. Where standing buildings are at risk of collapse, the method may entail the preparation of drawings and measurements, piece-by-piece disassembly, and careful reassembly, with new materials as required for structural integrity; occasionally this may include new foundations. When elements or parts are missing, modern materials (of restoration grade) may be substituted, such as plaster, cement, and synthetic resins.