Best practice external works and drainage

Issue date December 2016

Do not


Barbed wire, razor wire or spiked topped railings and fences must not be used.



All fences should be appropriate to their location and must not represent a risk to the users of the site or area (ie. rough cut timber fences to nursery play areas must not be used).

Planning: the following general planning rules apply to railings, fences, walls, gates etc:

  1. Planning permission is required if over 1m high and next to the highway.
  2. Planning permission is required if over 2m high and on a boundary.
  3. Planning permission is required if over 4m high and anywhere else.

Even if a proposal is strictly permitted development it may be unreasonable in planning terms if it affects neighbouring properties. In such cases a planning application should be made.

Care needs to be taken in conservation areas or next to listed buildings to ensure that any fencing chosen reflects the character of both.

Should be of a similar type to the two examples shown below:

bow top fence  vertical bar fence

Palisade or other industrial style railings/fences are generally not acceptable unless hidden from view (ie. buried with in a hedge).


Damage by animals
Care is taken in the selection of the planting specified and adequate protection from rabbits, deer or other animals is to be provided.

Adequate clauses to cover planting maintenance are to be included in the specification and enforced up to the end of the 12 month defect period. This should include:

  • regular visits during the growing season
  • weeding / general maintenance
  • use of fertilizer
  • pruning
  • watering
  • protective fencing
  • final mulching
  • future funding by establishment.

Position of plants
That planting is not positioned under any overhanging part of a building which prevents natural rainfall sustaining the plants.

Wherever possible seed should be used to establish grassed areas. Turf can be used if agreed with the Oxfordshire County Council Corporate Landlord (OCCCL) where new or repaired areas of existing grass need to be put into use immediately following completion or where it will be difficult to protect areas to allow grass seed to become established.

Security / safety
Where planting is used for security purposes (i.e. quick thorn hedging) appropriate consideration is given to the safety of children and users.

Sustainable drainage systems

Harmful effects of traditional drainage
Traditional drainage is designed to move rainwater as rapidly as possible from the point at which it has fallen to a discharge point, either a watercourse or soakaway. This approach has a number of harmful effects:

  • Run-off from hard paving and roofing can increase the risk of flooding downstream, as well as causing sudden rises in water levels and flow rates in watercourses.
  • Surface water run-off can contain contaminants such as oil, organic matter and toxic metals. Although often at low levels, cumulatively they can result in poor water quality in rivers and groundwater, affecting biodiversity, amenity value and potential water abstraction. After heavy rain, the first flush is often highly polluting.
  • By diverting rainfall to piped systems, water is stopped from soaking into the ground, depleting ground water and reducing flows in watercourses in dry weather.

As a result, many urban watercourses are lifeless and unattractive, and are often hidden in culverts under the ground.

The SUDS approach to drainage incorporates a wide variety of techniques to combat these issues and must be adopted wherever possible.

Information and guidance regarding SUDS is available on the Environment Agency website.

Roads, footpaths, car parks etc

It must be ensured that specifications for paved surfaces are appropriate for the intended use. Where possible surfaces are to be designed in conformity with the SUDS approach.

Paving slabs
Paving slabs must not be used in areas likely to be used by vehicular traffic.

Loose pea shingle / gravel paving infill
End users can regard it as a play zone and scatter the material over paths and playgrounds. The material can also be used by vandals. If considered then ensure that the Head of Establishment is aware of the possible problems in use.

Grasscrete blocks
Especially in dry conditions when the grass doesn't take the soil can blow or be washed out and create a trip hazard.

Do / ensure


Use weldmesh type panels and not chainlink. The size of the mesh must not allow children to gain a foothold to climb the fence.


Playing fields
Where a new playing field is included in the project the specification and the timescale allow the area to become established by the time the school opens.

Security and access

Padlocks for schools
Most schools have standard padlocks/ keys for their gates. These can be obtained from G&M Safety (01869 343480).