B&A Service 5

Independent tree assessment for development sites

An arborist would normally be able to disseminate the information required by individual planning authorities in relation to trees and development sites and therefore prevent unnecessary costs and re-draft times.

Your Local Planning Authority (LPA) are likely to ask for a 'Tree Survey' in line within the new British Standard, these can include though not limited to:-

Preliminary Tree surveys ,

Tree Constraints plans (TCP),

Arboricultural Implication Assessments (AIA),

Arboricultural Method Statements (AMS),

Tree Protection Plan (TPP),

We are very well experienced in the level of report and detail that may be required, we are here to save you and your design team time and money. If we are brought in at purchase or pre-purchase negotiations we can provide information upon a site developability whilst ensuring a 'tree friendly' and 'defendable' design is submitted.

The management of trees on development sites was recently revised with the publication of British Standard BS5837:2005 ‘Trees in Relation to Construction’, released in September 2005. To help developers and local authorities alike we help you meet these changes and we can provide various documents to support planning applications.

To enable this information to be used by members of the design team our visual information is supplied as separate layers within your normal AutoCAD package. Below are typical examples of a BS5837 Condition Survey, which tends to be the starting point of most surveys.

Trees that require additional information can be assessed in greater detail expanding upon the basic Visual Tree Assessment and allows us to comment upon the internal condition of the tree, presence of faults, extent of decay or structural defects.

Refer to our section on decay for more technical detail -

Tree survey Information is used to identify the arboricultural development window prior to create the most economical site lay out to satisfy the fiscal demands of the owner and the tree retention requirements of the LPA.

Once the scheme becomes more defined, the implications of the proposals can be detailed within a secondary report that highlights the likely areas of conflict in addition to proposing methods of mitigating damage / loss to trees. Various methods are available from above ground road ways to various foundations designs. We work with structural engineers to find the best foundation design and service routes to enable trees to be safely retained on sites.

On sites where the location of a unit is contentious, we can undertake a detailed investigation of shade issues brought about by trees. This details the loss that a householder may suffer, or demonstrates that light loss is restricted only to a particular time of day.

On sites where the scheme is already well defined, the above reports can be combined to offer both conditional information and site management information.

Occasionally a LPA may require a more detailed assessment on the site or require an exact timetable of defensive measures to ensure the retention of the trees is both reasonable and achievable. This information can be provided within an Arboricultural Method Statement. This document can cover the Arboricultural aspects of a whole site or be restricted to a single feature such as the creation of foundations within a tree protection area.

Photograph showing a recent development site with protective fence castings in place to prevent leachate from entering the soil profile and damaging valuable trees.

Such a document includes both the protective measures and the management of the site, by detailing the tree protection and management of trees from site acquisition, demolition, site layout, construction and landscape phase. We also provide site staff information leaflets and booklets / signage to help and encourage the site team to respect and care for the trees on site.

Where softening of the scheme is required, we can provide indicative planting plans, detailing the additional tree and vegetation to be established following the development phase.

Planting schemes can be either appended to the main Arboricultural Implication Assessment or presented as a separate document. These can be presented with a detailed specification or bill of quantities.

The retention of the right trees upon a development site can both settle the development within the local landscape and provide valuable screening between units. Correctly managed and maintained trees help to frame buildings and have been shown to add up to 17% to the value of a property, or simply make the property more saleable

Preliminary Site Assessments

At or before land acquisition, an arboricultural assessment (usually encompassing health & safety and inventory) of the site can allow an informed decision to be made in relation to the extent of development space available, the viability of development and / or where the development will be severely restricted by trees. This Pre-development Assessment allow's the economic potential of a site to be assessed.

Pre-Development Survey

Provides an assessment of the existing trees within a site to identify their condition and retention potential. The information is provided in accordance with BS5837 :2005 and allows the identification of development windows within the proposed development site to allow informed design and avoid problems like this.

Many local authorities require such an inspection before an application is registered.

Arboricultural Implication Assessment (AIA)

Indicating which trees are likely to be affected by the proposal, how and what considerations are being made to limit or mitigate foreseeable damage.

This assessment can identify where damage cannot be avoided and may identify special construction or engineering techniques to prevent damage often enabling the build to acceptable and approved where without special detailing the scheme would most likely fail.

We can provide case studies of sites which have achieved planning when alternative build techniques have been employed.

This report would also indicate essential tree works required allowing the development to continue, including 'facilitation pruning' to allow access to a site/location and supplementary considerations required where trees are lost.

The report would also outline the incorrect retention of trees on a site, often a short term gain when new planting would be perhaps more beneficial in the medium to long term.

Following an implication assessment or pre-development survey, and finalization of layout, an Arboricultural method statement would set out the processes required to initiate and manage tree protection zones. This would include a schedule of tree works for both safety and enabling, the position and type of fencing required, any additional surface protection required should the construction equipment be within protective zones, access routes, storage / wash out areas and post development site treatment.

Method statements are often adopted within planning conditions to ensure that developers take the necessary precautions in respect of trees / roots and avoid unnecessary conflict with trees or restrictions in work practices.

The method statement would be accompanied by a Tree Protection Plan (TPP) where trees for retention and removals are clearly shown.

Location to scale of protective fencing and type of is displayed on plan. The root protection area (RPA) is clearly represented to scale on plan. Constructional advisory drawings are also included where necessary.

It should always be remembered that areas for plantings should also be protected and not an 'after thought' on the site, these areas should be protected and the areas noted on plan.

Our inspectors can carry out weekly or monthly visits to active development sites to ensure that the developers are observing the requirements of their planning permission and or adhering to the conditions imposed this is becoming a more frequent request.

Ongoing site monitoring is essential to police the authorities policies whilst providing a professional opinion where problems arise. This not only reduces the LPA’s input into developments and reducing officer time, but provides a liaison between the developer and LPA ensuring that that both are confident of safe tree retention and enjoy uninterrupted build programs.

In order to reduce tree / root damage from various activities, e.g. trenching, storage, erection of site huts, arboricultural works etc, we can provide professional staff to oversee such works in order to prevent unnecessary damage that might be irreversible. Such supervision will ensure that specifications or planning conditions are met and provides a professional opinion when the unforeseen arises.

Specialist plant such as 'air picks' and 'air spades' can be utilized where appropriate we can provide specialist contacts in this respect.

Written specifications for arboricultural works / contracts can be drawn up to provide an up to date approach to many operations ensuring safety to trees, features and third parties.

A detailed specification allows performance monitoring creating a known objective for both the employer and contractors. This reduces the risk of low quality workmanship, damage or default by setting the standard from the outset.

We can offer professional contract management and tender preparation to enable the most suitable and cost affective contractor to undertake the works.

Preliminary Site Assessments

Pre-Development Survey

Arboricultural Implication Assessment (AIA)

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