Trees and development sites
a guide to best practice

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This page gives advice on how best to go about development when trees and landscape are a consideration -and of course they always should be. If there are trees there, they need considering, and if there are not, it's the ideal opportunity to plant some!

rees are good for our health, and the health of the planet. They can slow down wind and reduce heating bills; give shade and reduce summer electricity bills; absorb pollution; stabilise sloping sites; muffle noise. Trees on site may also provide sustainable crops of timber, other craft materials, fuel, and food. Trees can give shelter and food for other wildlife, especially if they form "green corridors" connecting the site to other trees and woods. Trees are beautiful and will give pleasure to the people who will live and work on the site, and to the people around. They may help to sell the development.

But you should not necessarily keep all existing trees. Trees grow, and you need to think ahead to avoid direct and indirect damage to new buildings. Some trees may be unsafe, and to make the site suitable for building you may need to remove them or have tree surgery done to make them safe. (If there are existing buildings on or next to the site, obtain advice on the risk of damage from heave before you remove any trees.) If potentially hazardous trees are left on site, purchasers might be able to claim for damage or for necessary tree surgery.

Building works can easily damage trees, especially the roots, and trees may then die back and become unsafe. You need to know before even designing the site which trees to keep and how to protect them, and consider where new planting would be appropriate and would not pose a potential future risk to people or buildings.

This page is intended as a basic outline of the process you should follow to choose which existing trees to keep, plan new tree planting, and to avoid breaching planning conditions. It is based mainly on guidance in DoE Circular 36/78, DoE guidance on Tree Preservation OrdersPages marked with this symbol are exclusively written for Naturenet, and BS 5837 (see below for details).

Advice before you make a planning application
Contact the local planning authority for an informal discussion if you want advice on the scope of the information you will need to provide before submitting your application. Relevant sections may include Development Control, Building Control, and Countryside.

Tree survey and site design
If there are trees on or next to your site, you should ideally submit a tree survey as part of your planning application. This will include the following work:

• Plot each tree trunk to within 1m and its existing ground level to within 0.1 m.
• Survey the trees, their condition, their landscape potential, and necessary surgery.
• Use tree survey to help decide site layout, tree retention, and new planting.

You are advised to employ a level surveyor, tree consultant and landscape architect to ensure good quality survey and design.

Planning application: tree survey plan
Submit the tree survey as a plan to an appropriate scale (usually 1:200 or 1:500) showing:

• Individually numbered trees and levels (trees to be removed as dotted lines; trees to be retained as solid lines).
• Position of protective fencing.
• Schedule of species, landscape value, diameter at breast height (dbh) which is 1.3m, crown spread, height, health, structural soundness, proposed tree surgery, and reason(s) for any removals.

Planning application: landscape plan
Submit landscape proposals as a plan to an appropriate scale (usually 1:100 or 1:200) showing:

• Existing and proposed levels (with sections as necessary).
• Positions and depths of buildings and foundations, paved surfaces, drainage, and services (water, gas, electricity, telecommunications).
• Trees to be retained, numbered as on the tree survey, and position(s) of protective fencing.
• New planting.

Planning consent and conditions
If your application is acceptable, you will probably be given planning permission subject to certain conditions. These will include conditions to retain and protect trees which the local planning authority consider are worth retaining. Trees may also be protected by Tree Preservation OrdersPages marked with this symbol are exclusively written for Naturenet.

On site: tree work
Employ a competent tree contractor to carry out tree work as detailed in the planning application:

• Remove any trees as necessary.
• Tree surgery work as necessary (for example, to make trees safe, or improve their shape, or open up views) to trees to be retained.

On site: protective fencing
Put up protective fencing around trees as detailed on the tree survey and landscape plan. This is to ensure that trees and especially tree roots are not damaged during building. The position and type of fencing will depend on the situation - you should seek the advice of a tree contractor or consultant, or ask the planning authority who will probably have guidelines available.

On site: construction work
Do not let anybody except the tree contractor onto site until the protective fencing has been put up. It will help to erect warning tape along the entire length of the fence - "TREE PROTECTION AREA - KEEP OUT". Make sure that all contractors and subcontractors have a copy of the planning consent with the conditions, and a copy of the approved plan (contact the copyright holder) showing the protective fencing. Make sure that anybody who comes on site knows that they are not allowed into the protected area(s). Make sure that the fencing stays up until building is complete, and that nobody enters the area, changes the ground levels inside it, or stores any material there.

On site:new planting
Make sure that the ground is left in good condition for planting new trees and other plants. Try to avoid overcompacting the soil, and relieve any compaction before planting. Rather than importing new topsoil, use topsoil from the site, improving it if necessary with organic matter such as composted green waste.

On site: completion and maintenance period
You will be required by planning conditions to ensure that any new planting is still there up to five years after completion, so either take responsibility directly by employing a tree / landscape contractor to manage the new planting to ensure it gets established, or make it clear to prospective buyers that this will be their responsibility.

Some useful publications

Your local planning authority maybe able to let you examine some of these.
Organisation
Title
Publisher
Date
BRE Low-rise building foundations: the influence of trees on clay soils BRE April 1999
BSI BS 5837 : 1991 Guide for Trees in relation to construction BSI 1991
BSI BS 3398 : 1989 Recommendations for Tree Work BSI 1989
BSI BS 3936 : 1992 Specification for Nursery Stock BSI 1992
DETR The Town and Country Planning (Trees) Regulations 1999 HMSO 1999
DoE Circular 36/78 Trees and Forestry Section X (replaced by the document below in so far as they relate to England. DoE May 1978
DoE Tree Preservation Orders: a guide to the law and good practice DoE 2000
NHBC Standards Chapter 4.2 Buildings near Trees NHBC 1997
NJUG Publication 10 Guidelines for the Planning, Installation and Maintenance of Utility Services in Proximity to Trees (pdf) NJUG 1995

This page is derived from advice prepared by Rowan Adams, former Tree and Landscape Officer, for the Isle of Wight Council. Reproduced by kind permission.