Policy DM7 Trees and development
Trees and significant hedge and shrub masses should be retained as an integral part of the design of development except where their long-term survival would be compromised by their age or physical condition or there are exceptional and overriding benefits in accepting their loss.
Development requiring the loss of a protected tree or hedgerow (including preserved trees, protected hedgerows, trees in Conservation Areas, ancient trees, aged and veteran trees and trees classified as being of categories A or B in value), will only be permitted where:
a) the removal of a tree or hedgerow will enhance the survival or growth of other protected trees or hedgerows;
b) it would allow for a substantially improved overall approach to the design and landscaping of the development that would outweigh the loss of any tree or hedgerow.
Where the loss of trees is accepted in these circumstances, developers will be required to provide at least equivalent replacement in terms of biomass. This should be provided on-site unless the developer can show exceptional circumstances which would justify replacement provision elsewhere.
Development affecting trees and hedgerows
Where a proposed development retains existing trees and hedgerows on-site, or where development occurs within a tree root protection area, provision must be made for their care and protection throughout the duration of the development with mitigation measures being put in place to ensure that development works do not have a harmful impact on existing trees.
Street trees
Major development proposals that have a frontage onto a new or existing highway of more than ten metres will only be permitted where they provide for the planting and maintenance of street trees of appropriate species at intervals appropriate to the site, except where the site’s location requires a clearly building-dominated design approach that would be prejudiced by the inclusion of street trees.
Supplementary text
7.1 Trees, hedges and shrubs add great beauty and sense of place and character to Norwich’s landscape and are a defining feature within the city. There are around 750,000 trees in the city, growing in a wide variety of locations. Trees enhance the structure and layout of the city, provide important landmarks, complement the built environment by providing screening, perspective, focal points, privacy and seclusion and they define and separate open spaces. They also provide habitats for a range of wildlife and form a “carbon sink” helping to absorb and store and counteract the harmful effect of carbon dioxide emissions. This policy, relating to trees affected by development, will further the council’s aim to preserve the variety, number and quality of trees in Norwich and to ensure that development contributes to the maintenance or enhancement of the tree cover of the urban area.
7.2 For the purposes of this policy, ‘protected trees’ include those protected by a tree preservation order, a tree within a conservation area, an ancient, aged or veteran tree or any other tree of category B or A as per BS 5837:2005 (as amended). The Woodland Trust and other sources state that there is no precise definition of an ‘ancient tree’ but there are three guiding principles: 1) trees which are of interest biologically, aesthetically or culturally because of their age; 2) trees that are in the ancient stage of their life; 3) trees that are old relative to others of the same species. A commonly accepted technical definition of an ancient tree is “A tree that shows characteristics of having passed beyond its mature phase.” Such characteristics might typically include a large girth, signs of crown retrenchment and hollowing of the stem.
7.3 The NPPF, similarly, defines an ‘aged’ or ‘veteran tree’ as “a tree which, because of its great age, size or condition is of exceptional value for wildlife, in the landscape, or culturally”. ‘Ancient trees’ are usually older than the majority of trees of the same species in the same geographic area, whilst a ‘veteran tree’ is one with similar characteristics to an ancient tree, but not necessarily ancient in years.
7.4 Consistent with the NPPF’s advice on protecting valued landscapes, the presumption of this policy is that existing viable trees, hedgerows and other shrub masses of value should be protected unless their loss is unavoidable. Where new development is proposed the preference will always be to incorporate trees and significant hedges and shrub masses into the development. Where the loss of any tree is unavoidable as part of a development, replacement provision is required and will be calculated in terms of replacement biomass rather than on a one to one basis. Where specific on or off-site planting proposals are negotiated as part of the overall enhancement of a particular development site, the replacement, protection and maintenance of trees, shrubs and other natural features would normally be specified by condition or secured by a planning obligation, either a section 106 agreement or unilateral undertaking. Larger scale enhancement of green infrastructure would be funded directly through the Community Infrastructure Levy (see the discussion of the role of the Community Infrastructure Levy following policy DM33).
7.5 Where a proposed development retains existing trees on-site, a satisfactory arboricultural impact assessment should be submitted in accordance with BS5837:2012 (or the equivalent applicable standard should this be superseded over the plan period) and the Norwich City Council validation checklist. This statement should analyse the potential impact on the retained trees. Where proposed development would have an impact on trees, particularly where it would impinge on root protection areas of trees both within and outside the development site, a site specific arboricultural method statement should be submitted. The statement should demonstrate mitigation measures are in place to ensure that development works do not harm the existing tree.
7.6 A supplementary planning document, Trees and development, has successfully supported the council’s previous policies in relation to trees and has been commended as an example of best practice. The document will be reviewed and updated as an advice note to support this policy, giving further detail on the recommended process to be followed to ensure appropriate protection and management of trees on development sites and to encourage the effective integration of existing and the provision of new trees and landscaping within development schemes.
References
- NPPF: CLG, 2012, Section 11 – Conserving and enhancing the natural environment: Minimise impacts on biodiversity and geodiversity, resist loss of irreplaceable habitats including ancient/veteran trees.
- National Planning Practice Guidance: CLG 2014: Natural environment; Tree Preservation Orders and trees in conservation areas.
- JCS policy 12: The remainder of the Norwich urban area, including the fringe parishes.
- Town and Country Planning Act 1990: s197 (as amended): duty for planning permission to make appropriate provision for the protection of trees.
- Natural Environment and Rural Communities Act 2006: s40, duty to conserve biodiversity.
- The British Standards Institute Standards BS 5837:2012; Trees in relation to design, demolition and construction.
