CAVAT: Recent changes and new guidance
If you’ve been using CAVAT or have integrated it into your Ezytreev system, we’ve got some recent changes to share with you. The revisions include a new Full Method and adjustments to the figures used for calculating both the Full and Quick Methods. Read on to find out more, and also for some useful guidance on how to apply the quick method.
CAVAT and how it is used
CAVAT is short for Capital Asset Value for Amenity Trees and was developed by Chris Neilan and the London Tree Officers Assocation (LTOA) in 2008. It has been widely adopted as a robust method by which a monetary figure can be assigned to the amenity value provided by trees in the UK.
Many local authorities and other tree managers use it in situations where their trees have been damaged, when dealing with subsidence claims, and for demonstrating the value of trees as part of development considerations. Councils regularly use it as the basis for seeking funding for offsite tree planting via s106 agreements, to offset the loss of trees to development.
There are two distinct CAVAT methods, the ‘Quick Method’ and the ‘Full Method’. The Quick Method uses the stem diameter of a tree to calculate the surface area of the cross-section of the trunk, then factors in the remaining Safe Life Expectancy (SLE) of the tree and a measure for the ‘Functional Value’ of the tree (as assessed by a surveyor) to arrive at a monetary value for the tree at that moment in time. The ‘Full Method’ performs a similar assessment but in considerably more detail.
The Quick Method is often used in tree inventories, where each individual or group of trees is easily assessed as part of periodic inspections and the resulting aggregate value helps to inform policies and decisions relating to part or whole of a tree stock. The Full Method is normally used where one or a handful of trees are the subject of damage, a claim or development proposal, where a more precise value for each individual tree is required.
Changes to the Full Method
In March 2023, the CAVAT group, comprising representatives from LTOA and the Municipal Tree Officers Association (MTOA), released an updated CAVAT Full Method, accompanied by a revised guide for practitioners. To conduct a Full Method assessment, you can use the revised official CAVAT calculator, available as an Excel file. This calculator can be downloaded onto your tablet or phone and a copy completed for any trees that require a Full Method assessment. Once back in the office, Ezytreev users can save the data as a PDF attachment against the relevant tree in their system for future reference, if required.
The Quick Method & Update to Monetary Value
The Quick Method itself hasn’t been changed by the CAVAT group review, but the Unit Value Factor (UVF) has been updated. This is the the figure that the calculator multiplies the CAVAT result by to give a value in Pounds Sterling, and is intended to be the value of 1cm2 of trunk surface area. It is reviewed periodically to ensure that new tree valuations are in line with inflation and the new UVF value is £24.59.
Attention, Ezytreev users! Check out our latest article published on ezyuserguide.com, where we explore how you can make the most of these updates to maintain precision and efficiency in your tree management practices. Read the full article here.
