SNPA Strapline


Maes y Waen, Penmachno


Trees and Planning

When considering planning applications the Snowdonia National Park Authority has to pay special attention to keeping trees as features of the landscape. An application which incorporates existing trees into the design is better than one which ignores them.

If the trees are sound and healthy it is always better to retain them than replace, as newly planted trees will take many years to reach maturity. Trees can also add to the value of a property.

Listed below are guidelines on how to proceed.

Trees and Planning, Betws Garmon

Trees and Planning, Betws Garmon (© SNPA)


A survey of the trees on site should be made right at the outset. The spread of their crowns should be measured and the total area occupied by each tree should be plotted accurately on the plan.

Are the trees sound and healthy?

Professional arboriculture advice may be needed. Trying to keep unsound trees may cause problems in the future.

How will the development fit amongst the trees?

Here the area of the crown spread is critical. It is not enough to design the development around the trees. To safeguard their roots it is essential that no work and no alteration in the soil levels takes place beneath heir crowns. The golden rule is to avoid any disturbance to the ground.

Plan Ahead

Remember to plan for water pipes, underground cables and drains, all of which must be kept away from the crowns.

Choice of trees to retain

Your design plans should show clearly which trees you intend to keep and which you need to fell. If a choice has to be made it is better to keep a young vigorous tree than one near the end of is life. But remember young trees grow larger and your plans should allow for this.

Will the trees be a nuisance in the future?

Except on clay soils, trees are seldomly responsible for damage to foundations but if there are poplars or ash trees close to the development you may need to take steps to restrict their root spread.

Tree Surgery

Many healthy trees have some dead wood in them. Get a professional arborist to carry out any necessary tree surgery before the development is started. Don't rely on cowboys who may seem cheaper. Someone will have to pick up the bill for the problems they create!

Avoid tree damage during development

Beware of damage to trees you are proposing to retain as the effects may not be obvious at once. The slow death of a damaged tree can result in considerable expense in felling it after the development has been completed. There are cases where a development has been designed around a tree feature which has been so damaged during construction that it has had to be taken down afterwards.

Leave enough space

Don't be tempted to squeeze buildings in too close to trees. People will have to live with them.

Some points to remember within the crown spread of a tree:

  • Do not take soil away or ad to it, even temporarily
  • Do not light fires
  • Do not store materials, chemicals or fuel
  • Do not excavate trenches
  • Do not allow machinery or vehicles to cross the ground
  • Erect no huts or structures
  • Beware of plant working nearby fouling branches

The only way of avoiding damage to the trees is to build a stout fence around the outside of their crown spread before any work is started and not remove it until all the work is completed. The Planning Authority will expect you to do this. It is in your own interest to do so.


For further information contact: Natural Environment and Forestry Service,
National Park Offices,
Gwynedd. LL48 6LF

Phone: 01766 770274
Fax: 01766 771211