Tree Surveys on Development Sites - Guidance for Developers
Where there are proposals to develop land and there are trees of amenity value that may be affected it is often necessary to request developers to carry out a tree survey. This is to help us to make a well-informed decision about the proposed development and its likely impact on the trees.
Guidance on such surveys is given by the British Standard Guide for Trees in Relation to Construction: BS 5837:2005. The following is a summary of the information required to comply with the Standard.
Tree Survey to include:
- Location and species of all trees over 75mm stem diameter measured at 1.5m above ground level, plus any smaller specimens of particular interest or potential value.
- Location of other arboricultural features such as shrub masses and hedges.
- Location of features such as existing and proposed buildings, services, streams etc.
- Spot heights of ground levels throughout the site as a basis for avoiding changes in soil levels around retained trees.
- Location of trees on adjacent land that may be affected by the proposed development or that may be of relevance to it.
- The height of each tree.
- Its trunk diameter at 1.5m above ground level.
- Its age class.
- Its crown spread (including its spread in each direction if it is asymmetric).
- Its health, condition and vigour.
- Its life expectancy.
- Any structural defects.
- Its size and form.
- Its suitability within the context of the proposed development.
The condition of all trees included in the survey should be assessed by a person experienced and competent in arboriculture.
The tree survey and assessment should lead to the categorisation of all the trees on the site into one of the following categories:
- Retention most desirable (high category).
- Retention desirable (moderate category).
- Could be retained (low category).
- Should be removed (fell category).
The information provided by the survey will help us to ensure the retention of valuable trees for the benefit of all. It will also be used to avoid situations where trees intended to be retained are lost as a result of damage during construction or because of other conflicts with built development.
Tree Protection Plan and Arboricultural Method Statement
Once trees have been identified for retention, further details will be required to show how they will be physically protected prior to, during, and post construction.
A scaled plan will be required showing all retained trees, their corresponding Root Protection Areas (as per BS 5837:2005) and the location and specification of protection barriers outside these protected areas.
The scaled plan should also include the proposed location of all plant and materials, storage, service and drainage runs, roads and driveways, existing and proposed new accesses and any other surface or underground features that may affect trees on the site.
For larger and more complicated sites, an accompanying Arboricultural Method Statement detailing all tree protection methodology, specifications and timings will be required.
For further details on tree protection please refer to BS 5837:2005 or contact the Council's Arboricultural Officer.
The Arboricultural Officer, Planning Policy & Heritage, The Guildhall, St Giles Square, Northampton NN1 1DE
Tel: 0300 330 7000
Email [email protected]
Date last reviewed: 23/04/2013