A growing number of local planning authorities are requiring calculations submitted as part of the planning application to demonstrate that the loss of canopy cover as a result of a development proposal can be compensated for over time. This is not the same as one tree planted for one tree removed.
Using the survey data, the existing canopy cover can be calculated. Mitigation planting can be proposed that will replace the lost canopy cover at a point in the future. This neutral canopy point can be adjusted by tree selection to balance the needs of the LPA against the opportunities of the site.
Tree valuation using CAVAT (Capital Asset Value for Amenity Trees) is used by Dorset Council Natural Environment Team Biodiversity Enhancement and Mitigation Protocol to assess off-site contributions where trees cannot be replaced on site.
I am an experienced CAVAT user and can undertake calculations to calculate, check or modify the off-site requirements.