Property valuations are undertaken as part of the process of obtaining a mortgage from a bank or other lender. If that property benefits from having trees in the garden or perhaps a tree or other woody vegetation is present in a neighbouring property, then that lender may insist on a mortgage report being obtained in respect of those trees. A report of this type should be undertaken by a qualified arboriculturist and will indicate which trees are relevant to the property, and it will report on the condition of those trees. It will also give an indication of the potential for those trees to cause damage to the property.

This damage may be caused directly by the tree for example by branches physically contacting the building during a storm. Alternatively it has the potential to cause indirect damage by affecting ground movement beneath the building's foundations.

Low rise buildings situated on shrinkable clay soil and with significant trees or other woody vegetation growing nearby may under certain circumstances be subject to movement caused by a moisture deficit within the soil. Trees use water and can have a desiccant effect upon the surrounding soil. However the degree of desiccation is the result of many factors, of which trees are only one.
A mortgage report will give an indication of the likelihood that adjacent structures will be affected by subsidence as a result of the tree's presence. Although very much an inexact science, an experienced arboriculturist can provide valuable information which will assist mortgage lenders and insurers to evaluate any risk.