Guidance

Annex D: Standard Cost Specifications

Updated 23 November 2020

1. Boundaries and stock proofing

1.1 Stone wall restoration

Stone walls need to be rebuilt to their original height in the local style. Farmers should refer to the height and style of other stone walls nearby that are in good condition.

Restoring the wall

• Take down the existing structure by hand, separating and sorting copings (covering stones), through stones and building stones for reuse
• Lay stones level and pack under each one so that it won’t move
• Always bring up the level of the middle of the wall for each course if using filling before going to the next one - it shouldn’t be possible to see daylight through the wall
• Place through stones where the wall is double-faced (they can’t stick out more than 15cm), so weight and stresses are spread evenly
• Place stones next to each other so they touch as much as possible, covering joints below as it is built (for example 1 stone on 2, then 2 stones on 1)
• Place each stone with its length reaching well into the wall, not along the outside
• Pack coping stones (stones placed along the top of the wall, ‘capping’ it) as firmly as possible to tie the whole wall together
• Finish the entrances and wall ends with a well-built cheek end
• The sides of the wall should slant evenly on both sides, creating an even ‘batter’ from a wide base to a narrower top of the wall. Avoid creating bulges as it weakens the wall and may collapse.

How to build the stone wall

• Dismantle the existing structure back to a sound construction
• Rebuild the wall so there’s an even top line, a consistent batter, and no bulges or depressions along the face of the wall
• Add a filling of solid rocks with each course where it’s part of the traditional construction
• Keep all existing wall-side trees and saplings
• Use wooden rails to make up any gaps - this allows for tree growth and stock-proofs the wall
• Rebuild stone features into the wall such as sheep creeps, troughs and stiles

What stone to use

• Use original stone where it’s available
• Make sure imported stone matches ones that are traditional to the area in type, size and style
• Haul stone only when ground conditions are firm enough to prevent damage to the fields next to the wall

Do not:

• disturb foundation stones unless it’s to create a firm base
• use topsoil, earth, sand or fine gravel as filling between courses
• use concrete or mortar
• take stone from other walls, banks or buildings on the holding
• place stone on features of archaeological, historic or wildlife value as identified in the farm environment record (FER)

Dispose of leftover materials

Remove any leftover materials used to complete the wall from the site and restore the ground where the work has been carried out.

Choose the right style for the wall

Restore the wall so it matches the stone types and wall styles in the immediate area. There can be distinctive local variations – often in relatively small areas. The style is determined by the composition, shape and size of the stone used and the way it can be split and shaped. Using the right type of stone will ensure the required style can be matched.

Stone wall supplement - difficult sites

This supplement can only be used on walls being restored using the stone wall restoration item. The walls must be:

• on a slope with an incline of more than 30 degrees
• greater than 1.6m in height
• in an inaccessible or remote location, for example a considerable distance from a track or is on boggy ground

Stone wall top-wiring

• Use round timber posts with a top diameter of 75mm
• Set the posts at centres no wider than 3m (for mild steel wire) or 10m (for high-tensile wire)
• Use posts long enough so that the top wire can be fixed at no more than 300mm above the top of the wall
• Use timber that is fully peeled and tanalised or treated with an appropriate preservative
• Knock the posts into the ground and either set them leaning against the wall or set them alternately on opposite sides of the wall
• Secure the posts
• Staple either half height sheep netting or 2 lines of steel wire 200mm apart to the upright posts
• Use 4mm diameter mild steel or 3.15mm diameter high tensile steel line wire
• Ensure the wire is properly strained and fastened with galvanised staples

Stone wall supplement – stone from quarry

• Use imported stone that matches the type, size and style of the wall being restored.
• Restore the wall as specified under ‘restoring the wall’.
• Remove all surplus stone from the site after work has been completed.

1.2 Post and wire fencing

• Remove all old fencing material before putting up the new fencing.
• Use softwood timber that’s fully peeled and tanalised, or treated with an approved preservative.
• Put up a fence at least 1.05m high.
• Use strands of galvanised 4mm mild plain steel wire or 2.5mm barbed wire.
• Use enough strands to control the livestock.
• Use straining posts that are at least 125mm by 125mm square (or have a 100mm top diameter) and are at least 1.87m long.
• Set the straining posts at least 750mm into the ground and no more than 150m apart.
• Place a straining post at every change of direction (horizontal or vertical) and at each end of the fence.
• Use struts that are 75mm by 75mm square, or have a 65mm top diameter, and 1.87m long.
• Set the struts at least 450mm into the ground and mortise them into the straining post.
• Use intermediate posts that are 75mm by 75mm square, or have a 65mm top diameter, and 1.75m long
• Set the intermediate posts at least 600mm in the ground and no more than 3.5m apart.
• Make sure that all the materials meet the relevant British Standards.

Do not:

• attach the fence to trees or hedgerows
• block or restrict access to open access land

Related items

This item can be used on the same length as the following items:

• Rabbit fencing supplement
• Fencing supplement – difficult sites

1.3 Sheep Netting (no top wire)

• Remove all old fencing material before putting up the new fencing.
• Use softwood timber that’s fully peeled and tanalised, or treated with an approved preservative.
• Put up a steel wire mesh fence at least 1.05m high.
• Use additional strands of galvanised steel wire (plain or barbed) if extra height is needed.
• Use straining posts that have a top diameter of at least 125mm top diameter, or are 100 by100mm in cross-section when sawn.
• Make sure the straining posts are 1.85m long if they’re set in concrete and 2.15m long if they aren’t.
• Place the straining posts no more than 150m apart if using mild steel line wire, or 300m apart for high tensile wire.
• Use a straining post at every change of direction (horizontal or vertical) and at each end of the fence.
• Use struts that have a top diameter of at least 80mm, or are 75mm by 75mm when sawn.
• Make sure the struts are 1.6m if they’re set in concrete and 1.9m long if they aren’t.
• Notch struts into the straining post at an angle of no more than 45 degrees.
• Use intermediate posts that have a top diameter of at least 65mm, or are 75mm by 75mm when sawn.
• Make sure the intermediate posts are 1.7m long and space them no further than 3.5m apart.
• Make sure that all the materials used meet the relevant British Standards.

Related items

This item can be used on the same length as the following items:

• Rabbit fencing supplement
• Fencing supplement – difficult sites

1.4 Rabbit fencing supplement

This can only be used where farmers are applying for restoration of fencing, for example, post and wire, sheep netting or permanent electric fencing.

Farmers must:

• use galvanised, 18 gauge, 31mm hexagonal wire mesh to construct the rabbit netting
• attach the netting to a pair of 2.65mm, high tensile, spring steel straining wires using galvanised netting rings
• make sure that one of the straining wires is at the bottom of the fence and one is at the top
• bury the bottom edge of the netting to a depth of 150mm, or lap the netting on the surface of the ground towards the rabbit threat
• anchor the lapped netting at 1m intervals
• make sure that all the materials meet the relevant British Standards

Fencing supplement - difficult sites

This can be used where the site being fenced:

• is remote
• cannot be accessed by vehicles
• is on steep slopes
• is prone to flooding or waterlogged for large parts of the year
• is in need of a lot of ground preparation

Farmers must complete the associated fencing to the relevant specification.

1.5 Deer fencing

Farmers must:

• meet the fence specifications set out in table 3 (and in the Forestry Commission’s technical guide Forest Fencing 172)
• clear debris from the line of the fence
• make the line of the fence smooth enough that the bottom of the fence sits with the ground (there must be no gaps that deer can enter through)
• make sure the fence is regularly inspected
• maintain the fence so that deer can’t enter the land

Specifications for the fence woodwork

Species	Endposts and turning posts (m by cm)	Struts (m by cm)	Intermediate takes (m by cm)	Maximum stake spacing (m)
Roe	2.8 by 10 to 13	2.5 by 8 to 10	2.5 by 5 to 8	10
Muntjac	2.8 by 10 to 13	2.5 by 8 to 10	2.5 by 5 to 8	10
Red/sika/fallow	2.8 by 12 to 18	2.5 by 10 to 13	2.6 by 8 to 10	10

Specifications for the height of the fence and the size of the mesh

Species of deer	Minimum fence height (m)	Maximum mesh size (mm)
Red and sika	1.8	200 by 300
Fallow	1.8	200 by 220
Roe	1.5	200 by 150
Muntjack	1.5	75 by 75

1.6 Permanent electric fencing

• Erect wire fencing at least 1050mm high using a minimum of 4 mild steel or high tensile plain wires.
• Use straining posts with a top diameter of at least 150mm and 2150mm long, spaced according to the type of wire used.
• Use struts with a top diameter of least 80mm and 2100mm long, notched into straining posts.
• Use intermediate posts with a top diameter of at least 63mm and 1700mm long, spaced according to the type of wire used.
• Install a mains-operated energiser in accordance with the Institute of Electrical Engineers IEEE Regulations.
• Make sure that all the materials meet the relevant British Standards.

Related items

This item can be used on the same length as the following items:

• Rabbit fencing supplement
• Fencing supplement – difficult sites

2. Gates

2.1 Wooden field gate

If the area has a local style then the gate should be constructed to match, including using the same timber. If there is no local style then the following specifications should be used:.

Section	Gates up to 3m wide	Gates 3m and over wide
Top rail	100mm by 75mm	125mm by 75mm
Top rail tapered to	75mm by 75mm	75mm by 75mm
Under rails	75mm by 25mm	75mm by 25mm
Braces	75mm by 25mm	75mm by 25mm
Hanging style	100mm by 75mm	125mm by 75mm
Shutting style	75mm by 75mm	75mm by 75mm

2.2 Wooden field gates - for all styles

Hang and clap the gate separately from an adjoining fence line - don’t use the hanging post as an end strainer.

Then do one of the following:

• set gate posts at least 900mm into the ground and surround with concrete at least:
  • 450mm by 450mm wide
  • 600mm deep
• Erect gate posts without concrete surrounds and set at least 1.1m below the ground surface with the soil compacted around the posts in 150mm layers

Weather cap the top of the gate posts.

Constructing the gates

Frame the gates soundly and use wooden materials. All gates should match in height with the adjoining fence and be fitted with the appropriate fittings for their operation. If gateways need widening during wall or bank restoration, or to create a new opening, planning permission may be needed. Consult the National Park authority or the local planning authority about hedgerow regulations and the permission needed.

2.3 Galvanised metal field gate

Make sure that the galvanised metal field gate meets the relevant British Standards.

Hang and clap the gate separately from an adjoining fence line - don’t use the hanging post as an end strainer.

Then do one of the following:

• set gate posts at least 900mm into the ground and surround with concrete at least:
  • 450mm by 450mm wide
  • 600mm deep
• erect gate posts without concrete surrounds and set at least 1.1m below the ground surface with the soil compacted around the posts in 150mm layers

2.4 Stone gate post

Set up a stone or slate gate post in the local material, cut or tooled to the size and shape typical of the local area.

2.5 Water gates

Fit a gate across the river or stream. Make sure that the gate:

• is framed and made of wood
• fits the profile of the river or stream
• matches the fence next to it in height
• uses timber that’s fully peeled and tanalised or treated with an approved preservative
• can float up and down as the water levels rise and fall
• has an approach fence that’s either a post-and-rail or fixed netting fence
• is separate (along with the approach fencing) from the main fence line
• meets the relevant British Standards - examine copies of the most up-to-date standards

The gate must consist of a series of wooden droppers attached to a length of wire cable, or a round wooden rail suspended horizontally between straining posts. The droppers must be:

• at least 50mm square in cross section
• made from sawn, untreated timber that’s been drilled and then threaded on to the cable or rail
• separated by 150mm lengths of plastic pipe

If the stream gully is more than 1.5m deep, construct the gate in several sections. The droppers must be:

• made of untreated timber
• at least 70mm square
• hung on round wooden poles using loops of fencing wire

3. Earthworks and groundworks

3.1 Resurfacing of gateways

All the capital works carried out must meet the relevant British Standards. Examine copies of the most up-to-date standards for guidance.

• Excavate the full width of the gateway to the full length of the gate opening into the field when the gate is open 90 degrees.
• Excavate to a minimum depth of 150mm or until there is a naturally occurring sub-base.
• Remove the excavated soil from the gateway area and spread it on the verges of the field track, allowing for drainage.
• Overlay the excavated area with a geotextile membrane, then fill with aggregate (hard core) to a minimum consolidated depth of 150mm.

Materials and resurface area

When carrying out the work:

• the area to be resurfaced should be relative in size to the gateway and the type of traffic that will move through it
• compact down each layer of hard core well before adding another layer, making sure each layer is no more than 150mm thick
• advice must be received from the Environment Agency (EA) if road planings, waste or recycled materials will be used as hard core

Gateway relocation

All the capital works carried out must meet the relevant British Standards. Examine copies of the most up-to-date standards for guidance.

• Leave the existing gate posts where they are, keeping any existing stone or slate posts that are traditional landscape or historic features.
• Re-route the existing trackways associated with the gateway and make good the disused sections.
• Gap up the old gateway using materials that match the character of the rest of the boundary.
• Use new hanging and shutting posts in the new gateway.

3.2 Watercourse crossings

All the capital works carried out must meet the relevant British Standards. Examine copies of the most up-to-date standards for guidance.

• Construct a ford at least 4m wide.
• Key a semi-circular, straight or oblique group of toe stones into the riverbed on the downstream edge to form a gravel trap.
• Key the stones down to at least 600mm below the existing level of the bed or below the known scour level (whichever is deeper).
• Make sure the stones do not stand clear of the water during low summer flows and that they do not form a weir.
• Make sure the approach slope gradient is no steeper than 1 in 4.
• Make sure that livestock can’t access the sides of the ford approaches.
• Include rock revetment to protect the ford approaches on the river side.

Farmers must also protect the base of the entrance and the exit ramp, as this will help to prevent bankside erosion. Use either rock armouring or coarse gravel or hardcore for protection. If rock armouring is used cobble-sized rocks should be used to create as flat a surface as possible. Fill any gaps with coarse gravel or hardcore.

If coarse gravel or hardcore are used:

• use them with treated retaining boards (50mm by 230mm) along the ramp (parallel to the river flow) and spaced 1m apart
• hold the boards in position with treated posts (100mm by 100mm) that are 1m apart
• drive the posts into the bank and trim them at an angle of 1 in 4 (parallel to the slope)
• drive the posts at least 50mm below the line of the boards to avoid tripping
• compact the bed of the ramp to provide a stable footing for livestock.

3.3 Cross drains

All the capital works carried out must meet the relevant British Standards. Examine copies of the most up-to-date standards for guidance.

How to construct a cross drain

• Position the cross drain so it catches the water on the upper side of the track or yard and transfer it to an outfall where it will not cause new erosion or runoff issues.
• Redirect water from the cross drain to a stable drainage outlet such as a ditch, culvert or other outfall - low flows can be directed to a field or field margin.
• Construct the drain either by digging a partially covered channel to collect sediment and redirect surface water, or by constructing a low hump to direct surface flows.
• Maintain drains and drainage outfalls or the areas around humps by removing built-up sediment or other clogging materials.

How to construct a channel

• Excavate a channel across the width of the track or in a yard that’s at least 100mm deep and 100mm to 250mm wide.
• Line the channel with concrete and install a gridded top that must be at least 150mm wide. How to construct a raised hump To construct a raised hump, successful applicants will need to:
• excavate a foundation trench across the track or yard that’s at least 300mm deep
• fill it with concrete
• key in kerbstones across the trench so they protrude 60 to 100mm above the surrounding surface.

Installation of piped culverts in ditches

All work must:

• meet relevant British Standards. Culverts must be constructed using concrete pipes that comply with BS 5911 and BS EN 1916. Pipework must be laid in accordance with BS 8000 - examine copies of the most up-to-date standards for guidance
• comply with the culvert design and operation guide (C689)
• Install a concrete pipe that’s at least 450mm in diameter following the manufacturer’s instructions.
• Make sure that pipes have a positive joint to preserve alignment.
• Make sure that the pipe lengths give a useable width at ground level that is appropriate for the traffic using the crossing, with the minimum width for a culvert:
  • 4m for wheeled traffic
  • Less than 4m acceptable for livestock footpaths and bridleways
• Set the pipes on a firm bed and in true alignment.
• Make sure that the pipe gradient is approximate to that of the ditch bed
• Make sure that the pipe invert (the level of the inside bottom of the pipe) at the upstream end is fractionally below the bottom of the true ditch bed.
• Grade the ditch bed downstream if any deepening is needed to accommodate the culvert.
• Maintain the culvert for the duration of the agreement, removing debris that builds up so as to maintain flow.

Where the above standard specifications for the culvert are not suitable for the weight of machinery using the crossing applicants must obtain advice from a drainage or bridge engineer and complete the works in accordance with their advice. Farmers are responsible for ensuring the culvert does not collapse.

3.4 Earth banks and soil bunds

Design and construction

Famers are likely to need to:

• form infiltration basins into ‘V’, ‘U’ or ‘C’ shapes
• measure bunds in a continuous length of 100m per unit with up to a 250m2 runoff store
• dig down 0.8m in depth
• grade side slopes to no more than 1 in 3
• make sure half the stored water can empty within 24 hours
• flatten the soil when damp to strengthen the structure
• plant grass species in banks that can withstand wet and dry conditions
• establish vegetation on the basin floor to reduce clogging
• build bay silt traps where soil erosion is high to stop the basin from clogging
• regularly remove excess sediment from banks and bunds, reapplying it back to the field (contact the Environment Agency to check if a waste exemption is required)

To enhance buffer strips

• place soil bunds at the field edge of buffer strips, this slows runoff
• build bunds 300mm to 500mm high by 600mm to 1000mm wide
• place larger bunds where complex field slopes divert runoff to pinch points

Establishing soil bunds

Compact down soil bunds then sow a seed mixture at a rate of 24g/m2. Form the seed mix from grass, legumes and wildflower, for example:

• creeping red fescue (70%)
• smooth meadow-grass (20%)
• creeping bent (10%)

Building weirs and outlets

Weirs and outlets can be built into the design as they can discharge more water than pipes and are less likely to block up. The water should be directed onto stones or boulders to slow flow for piped overflows or weirs in ditches and ponds.

4. Miscellaneous

4.1 Livestock troughs

• Make sure the trough is made of galvanised steel, or concrete, spray-moulded glass-reinforced cement (GRC), or polyethylene
• Make sure the trough has a ball valve and service box
• Connect the trough to a water supply or to water supplied from a bowser on a regular basis
• Meet the Water Supply (Water Fittings) Regulations 1999 if using a mains water supply
• Make sure the trough meets relevant British Standards

Pipework associated with livestock troughs

• Make sure the pipework is made of medium-density blue polyethylene and has an external diameter of at least 25mm
• Make sure that all the joints are made of brass or plastic and that they’re watertight
• Bury the pipework below the cultivation depth and to at least 600mm (or as determined by the local water supplier)
• Cover the pipe with a tubular steel guard or sleeve pipe if it crosses an open ditch
• Lay the pipe 600mm below the ditch to allow for ditch cleaning
• Lay the pipe on a 75mm bed of sand if it crosses farm tracks and then cover it with a further 100mm of sand, before overlaying it with backfill
• Make sure that the pipe meets the relevant British Standards