The valuation of amenity trees is often critical in resolution of damages and insurance claims. There are a number of industry standard valuation models:
- The Helliwell System – first introduced in 1967, the system assesses the visual amenity of a tree, or a woodland, under a number of categories, arriving at a score which is converted to monetary value through a regularly updated conversion factor.
- The CAVAT system, which assesses the Capital Asset Value for Amenity Trees based on extrapolated replacement costs, can be used to value individual trees as well as tree stock collectively.
- The CTLA system uses valuation methods from the Council of Tree and Landscape Appraisers in the US, to provide discounted replacement costs.
The three systems often result in widely varying results. A full understanding of the systems, a thorough academic approach and a common sense link with reality are essential for a valuation that will be accepted by insurers or the courts.