Reversibility
The conservation principle that interventions should be capable of being undone in future, preserving the option to apply better methods when they become available.
Reversibility is the conservation principle that interventions should be capable of being removed or undone in the future without damage to the original fabric. The principle recognises that conservation knowledge improves over time — methods considered appropriate today may be found harmful in future, and better approaches may be developed.
In practice, perfect reversibility is rarely achievable — any physical intervention leaves some trace. The Venice Charter requires that conservation measures should be 'reversible as much as possible.' The INTACH Charter similarly emphasises that 'techniques and materials used should ideally be reversible or at least retreatable.'
Common examples of reversibility requirements: use lime mortars (softer than stone, removable without damage) rather than cement (which can cause spalling); use consolidants that can be dissolved and removed; make repairs distinguishable and documentable so they can be identified and revised in future.