Quantified Tree Risk Assessment Survey (QTRA)

As licensed users of the QTRA system, we offer risk assessment surveys and reports. This tree survey method provides a quantitative analysis of risk that people or property will be harmed or damaged due to tree failure. This method is a generally sympathetic approach to tree management which ensures compliance with the Occupiers Liability Act 1954/1980 through undertaking regular surveys. The benefits of this system allow for tree retention where statistical analysis shows that the risk of harm is considered tolerable.

This type of survey can be provided as complimentary to other types of tree surveys or as a standalone assessment. By separating areas that either contain potential targets i.e. people and property, to those without, large tree populations can be surveyed in shorter periods of time. This can provide a more economical approach for larger estates with large quantities of trees but relatively few potential risks.

Ecological Surveys

Impact Assessments

Environmental Planning


Biodiversity Net Gain