The Greek government has a special department committed to the preservation of ancient sites and temples known as the Department of Antiquities. This department produced a plan in 1975 called the Acropolis Restoration Project, which is geared towards repairing and preserving the Parthenon and other Acropolis sites.
The projects goals are to repair damage from pollution, wars, decay, and other misguided restorations by strengthening the structure with titanium rods. The project also calls for the use of original materials whenever possible and for all restorations to be completely reversible in case future technologies are developed that are better.
Some specific successes of this project are the correct reassembling of the colonnades, which had been destroyed in a 17th century war and misassembled. The roof and floor have been partially restored with one section of the Propylaea being redecorated with the original blue and gold inserts. The Temple of Athena Nike is also being restored, and has been so successfully reassembled it will appear virtual intact when everything is finally complete.
All in all, more than 2,600 tons of materials were utilizes to reassemble the temple, but only 530 cubic meters of it was new.