Damaged artwork: how the loss of value is assessed

What a work is worth after damage does not depend only on the cost of restoration. How the damage is quantified and what the remaining depreciation depends on.

Guide · 4 min read · reviewed in 2026
For whom: private owners and families · insurance brokers · lawyers · companies

When a work of art is damaged, the question is not only how much it will cost to restore it, but how much value it has lost. The two figures rarely coincide: even a successful restoration often leaves a loss that the market recognises, and a damage appraisal serves to determine it and explain it.

The method

The starting point is the value of the work immediately before the event, and which value is used depends on the situation. If the work is insured on an agreed value basis, that is, with a value fixed in writing by the insured and the insurer, usually on the basis of an appraisal, the value is the agreed one. If the policy only contains a value declared by the insured, the market value the work had before the event has to be demonstrated. If the work is not insured, or if the damage is claimed from whoever caused it, the appraisal determines the fair market value immediately before the event. Coverage, deductibles and settlement terms remain a matter for the broker and the insurer.

The "before" is reconstructed from documents, photographs, condition reports and previous valuations: a work that has already been described and photographed has a demonstrable "before"; a work without documents does not. Alterations already present before the event must be identified and are excluded from the damage.

Whether the work can be restored, what the treatment involves and what it costs is established by a conservator specialised in the work's materials. The appraiser reads the conservator's quote and distinguishes what restoration can recover from what remains irreversible.

The damage therefore consists of two separate items: the cost of restoration and the depreciation, that is, the loss of value that remains even after a successful restoration. The value after restoration assumes that the treatment succeeds, and the appraisal states this. Together the two items cannot exceed the value of the work before the event: if restoration costs more than the work is worth, the treatment makes no economic sense and the damage equals the full value.

What depreciation depends on

There is no fixed percentage: depreciation is assessed work by work, considering in particular:

the nature of the alteration, its extent and how far it interferes with the image: a stain on the margin weighs less than damage within the image or on the signature;
the expected outcome of the restoration, its stability and how visible it will remain;
previous damage and restorations;
the importance of the work: for rare works, or works central to the artist's career, condition has a greater effect on price, and damage weighs more;
how the artist's market receives restored works, checked against sales of comparable works with documented restorations, where they exist.

For some types of work, such as works from the second half of the twentieth century made with modern materials, even limited treatment can weigh heavily on value.

Before and after restoration

The loss of value can also be determined before treatment, but the condition of the damaged work must be documented before any intervention: photographs, the conservator's condition report, keeping any fragments. Once carried out, the restoration must be documented and disclosed in every subsequent appraisal, even when it is not visible to the naked eye.