Tree condition & risk assessment

We assist tree owners in taking a balanced and proportionate approach to tree safety management. Depending on the requirements of our clients, we carry out tree surveys appropriate for their needs and budget.

Under the occupiers’ liability acts of 1957 and 1984, owners of land on which a tree stands have a duty of care to all people on or near that land, who might be injured by the tree. It is the duty-holder’s fundamental responsibility, in taking reasonable care as a reasonable and prudent landowner, to consider the risks posed by their trees.


Thinktrees Ltd. is called in to assist tree owners in taking a balanced and proportionate approach to tree safety management. These extend from a basic ‘walk-over’ survey, where only those trees that require work to be carried out within one year for health and safety reasons are recorded, to inventories, which involve the inspection and recording of all trees within a population. Paul Melarange is a licensed user of the ‘QTRA’ (Quantified Tree Risk Assessment) system, which is particularly useful when carrying out ‘walk-over’ surveys, but can also be used to prioritise tree work recommendations made during a full inventory.



Fruiting bodies of Honey fungus (Amillararia sp.) around the base of a tree.



Full inventories of all the trees in a given area enable population analysis to be carried out. This provides an overview of the condition of the tree stock and can be used to indicate its long-term management requirements in terms of both sustainability and health and safety. Detailed tree inspection also enables an assessment of vitality and structural condition to be made for each tree. Following this assessment, recommendations for remedial work may be made for those trees that demonstrate reduced vigour, possess minor defects that may progressively worsen over time or where the growing environment is sub-optimal. This level of management would not normally be included in a ‘walk-over’ survey as the implications of such defects are, as far as health and safety is concerned, likely to be inconsequential in the short-term.


The use of GIS (Geographical Information System) and database software enables us to plot the locations of trees and record details of their condition and management requirements. This information can then be illustrated as plans and schedules, so as to make it understandable and accessible to anyone who requires it.


Contact us for more information or to discuss your requirements



Weeping Willow in the centre of Bishop's Stortford, Hertfordshire

Tree expert testing a pine tree for decay using an Arbotom impulse tomography unit



T: 01524 782229   E:

Cumbria office:
Thinktrees Ltd

9 Farleton View Holme


Bishop’s Stortford office:

Thinktrees Ltd

68 Chantry Road

Bishop’s Stortford


CM23 2SG


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