Access our Foundation Depth Calculator

Our Foundation Depth Calculator is designed to enable the user to easily determine the exact foundation depth required when building near trees. The depth of foundation is determined by inputting:

  Plasticity index of soil

  Water demand of the tree

  Mature height of the tree

  Distance of relevant tree to nearest part of foundations and distances elsewhere if stepping foundations

  Allowance for climatic conditions

The Foundation Depth Calculator includes the vast majority of trees found in the UK, however it does not include every single tree.  If a tree is not listed you should consult a structural engineer and an arbor culturist for advice.

You can refer to the Technical Manual for more details on foundation depth.