The insurance value of your objects should enable you to replace lost objects by a similar object available on the market. We use the Dutch standard 'Vervangingswaarde ex art 7:960 BW voor taxatie door deskundigen' (previously art. 275 Wetboek van Koophandel). When an object is damaged, you should not only be insured for restauration charges by a professional but also for the depreciation of the object's value.
Most insurance companies expect an updated valuation report every three to four years. A regular re-valuation is the best way of insuring your collection at the right level. Market developments since the late 20th Century have shown increasing and substantial fluctuations of the value of art and antiques. For objects that have seen a significant increase of value it is useful that your insurance covers its current value. Revaluation may create recurring costs, but you remain insured at the accurate level. At the same time you do not want to pay too much insurance premium for objects whose value has gone down. We have seen cases where outdated valuations turned out to be twice as high as the current value causing a much higher premium than necessary. In these cases the reduction in premium entirely compensated the revaluation costs. If your collection frequently fluctuates in numbers and value, it thus may be useful to update your valuation report accordingly.