It is important to consider trees early in the planning process, and BS 5837:2012 ‘Trees in relation to design, demolition and construction’ gives national guidance on the correct procedures required to satisfy requirements for planning.
Existing trees are an important factor on development projects and construction sites, whether on or near the working areas, and trees are a material consideration in the UK planning system. British Standard BS 5837:2012 is intended to assist decision making with regard to existing and proposed trees.
Trees can offer the built environment many benefits, and are important elements of green infrastructure, contributing to cooling through evapo-transpiration and providing micro-climatic effects that can reduce energy demands in buildings. They therefore represent a key resource that can significantly contribute to climate change adaptation.
Root systems, stems and canopies, with allowance for future movement and growth, need to be taken into account in all projects, including those that do not require planning permission. The space required for any proposed new trees to become established is an important consideration.
During their lifetime, trees will be vulnerable to disturbance, injury, environmental changes, pests and diseases. Construction work often exerts pressures on existing trees, as do changes in their immediate environment following the construction. A tree that has taken many decades to reach maturity can be damaged irreparably in a few minutes by actions that might be unwitting, negligent or wilful. The early provision of physical protection from damage is therefore critical.
Where tree retention or planting is proposed in conjunction with nearby construction, the objective should be to achieve a harmonious relationship between trees and structures that can be sustained in the long term. Good practice recommended by the British Standard is intended to assist in achieving this objective.
Arboricultural Impact Assessment (AIA)
Quants has 5 core staff who are trained to undertake high quality Arboricultural Surveys and Tree Constraints Plans in line with BS 5837:2012. An evaluation of the effect of the proposed development on the trees can be determined in an Arboricultural Impact Assessment (AIA). Frequently requested as part of a planning application, the AIA details the likely impact that the design will have on existing trees.
The AIA includes a Tree Protection Plan, visually illustrating the tree protection and special construction measures required. An Arboricultural Method Statement (AMS) gives precise details of how retained trees will be protected during construction, and how works within the Root Protection Areas (RPAs) of retained trees will be undertaken without detriment to the future health of the trees.
The AMS is usually drawn up once planning permission has been obtained and the construction phasing decided. However, local planning authorities can ask to see generic method statements at the planning submission stage.