The museum conservators face the problem how to preserve the frescos in the museum. Should they not to strive to preserve every last atom of the original fabric in the state in which it has come down to us, making all works of necessary conservation wholly reversible, recognising that future generations may have access to better techniques. The ideal that their conservation procedure represents is not altogether irrelevant in a building conservation context. In fact, there is total unanimity in the museum conservation world and yet the conservators still need to compromise. If the conserved work is seen finally to be something separate from the building structure, then we must admit that the artist’s intention has been modified and to that extent the whole meticulously careful process had led to loss in term of both historic record and aesthetic intent. The problem arise from the fact that conservation in these terms is a highly artificial procedure which attempts to arrest, if not eliminate, nature process of change and decay. The arguments sound almost unanswerable, but there will still be those who will say that the interference with the original material has nevertheless been too drastic and in some respects is irreversible. The impression of completeness is quite false and the devices used to distinguish modern from original work simply laughable. Other than museum, some buildings do in some respects have the character of museum objects, but the problems they pose are likely to be far more complex and the compromises they lead to at least as open to debate as any that face the museum conservator.
(John Earl, 2003, Building Conservation Philosophy, 3rd Edition, Donhead Publishing)