Foundation Depth Calculator

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 arboriculturist for advice.

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