How to Plan a Garden Fence: Sizes, Heights, Posts and Gravel Boards

A good fencing project starts before you order the panels. Measuring your boundary, choosing a construction style and checking the finished height can help you avoid mismatched materials and extra trips for forgotten parts.

This guide from Grasmere Garden Centre in Brownhills covers the planning decisions: panel styles and sizes, concrete versus timber, gravel-board finishes and the main fence-height planning rules for homes in England. It is a starting point for your materials list, rather than a site-specific installation specification.

1. Measure the boundary, not just the old panels

Sketch the fence line and measure each straight section separately. Mark corners, gates, changes in level and any posts you hope to reuse. Keep your measurements in one unit, preferably millimetres, so you can compare them with product dimensions.

If you are replacing panels between existing posts, measure the actual opening and the way the panel fits into its supports. Check more than one position rather than assuming every gap is identical. Record the condition of the posts and gravel boards too: a new panel alone may not solve a problem with its supports.

Before work starts, establish the boundary position and any access arrangements with your neighbour. Do not assume the old fence marks the exact legal boundary.

Before you dig

Check for buried electricity cables, gas and water pipes and other services before digging post holes or driving in spikes. Obtain available service plans and arrange for buried services to be located and identified; plans alone are not a substitute for locating them on site. Use a competent contractor if you cannot establish a safe method of work. If the route of a service is uncertain, stop and seek advice from its owner or operator before proceeding.

The HSE’s guidance sets out three essentials: planning the work, locating and identifying buried services, and safe excavation. Read Avoiding danger from underground services before work begins.

2. Feather-edge or waney-lap: what is the difference?

Feather-edge (left) and waney-lap (right). These examples show different panel heights and are not shown to scale.

Feather-edge fencing

Feather-edge boards have a tapered cross-section, with one edge thinner than the other. In typical garden fencing, the boards run vertically and overlap to form a closeboard face, supported by horizontal rails. You can buy ready-made feather-edge panels or build a closeboard fence on site from individual boards, rails and suitable posts.

The result is a fairly uniform, upright appearance. Feather-edge is often chosen for a substantial-looking privacy boundary. However, the name alone does not guarantee strength: board thickness, overlap, rails, fixings and the supporting posts all matter. Timber movement can also affect gaps over time.

Waney-lap fencing

Waney-lap panels use overlapping horizontal timber slats with irregular, wavy edges. These give the panel its familiar layered, rustic appearance. The slats are held within a framed panel rather than assembled as individual vertical boards along the fence line.

Waney-lap is commonly a budget-conscious choice for a garden boundary. Compare the actual product prices and construction rather than assuming every lap panel is cheaper or every feather-edge panel is stronger.

Which should you choose?

Choose the appearance you prefer, then compare the specification and your site. Waney-lap gives a horizontal, traditional look; feather-edge gives a vertical, closeboard look. Neither style should be treated as automatically suitable for a very exposed site. The complete installation, including posts and foundations, needs to suit the conditions.

Compare our fence panels, checking their actual dimensions, treatment information and construction.

Building closeboard from individual materials

We stock individual feather-edge boards, arris rails and cant rails for closeboard projects. Plan the system as a whole: rail type, post design, board overlap and spacing need to work together.

Do not estimate the number of feather-edge boards using their full width alone. Overlap reduces the width each board covers. Use the supplier’s specified overlap and construction details when working out quantities.

Explore our fencing range to compare the materials before settling on your layout.

Tanalised, pressure-treated or dip-treated timber?

Pressure treatment uses an industrial vacuum-pressure process to drive preservative into the timber, rather than simply coating its surface. Tanalised® is a treatment brand associated with Tanalith® preservative, not a generic guarantee that every piece of green timber has the same protection.

Dip treatment involves immersing timber in a preservative solution that is absorbed into its surface. It provides initial protection but needs ongoing care. Follow the particular supplier’s instructions: for example, Forest Garden specifies annual retreatment for its dip-treated products and advises keeping its dip-treated panels out of direct ground contact by using gravel boards.

Pressure-treated timber generally reduces the need for routine preservative retreatment compared with dip-treated timber, but it is not rot-proof and does not make every component suitable for burial. For timber posts installed in the ground, specify treatment suitable for ground contact, commonly described as Use Class 4. Check the treatment specification for gravel boards too.

Choose by the stated treatment and intended use, not colour. Brown timber can also be pressure-treated, and a greenish colour alone does not confirm a particular treatment standard. Follow the manufacturer’s instructions for any cuts or drilled holes and use the specified end-grain preservative where required. Surface treatment of a cut does not turn unsuitable timber into a ground-contact post.

Further reading: Tanalised timber and ground-contact specifications and dip and pressure treatment explained by Forest Garden. Treatment details and guarantees vary by supplier; these explanations are not guarantees for every product in our range.

3. Understand panel sizes and finished fence height

A product described in feet may also have metric dimensions. For reference, 6ft is 1.8288m, not exactly 1.8m. Check the actual dimensions on the product page rather than treating these measurements as interchangeable.

Panel height is not necessarily the finished height of the fence. Account for any gravel board beneath it, any trellis above it and the way the components fit together. Measure the proposed finished structure from ground level, not just the timber panel.

Sizing example: a panel that is actually 1,800mm high above a 150mm gravel board gives a nominal combined height of 1,950mm. That assumes the full board height is above ground and the components meet without overlap or extra gaps. It is a planning calculation, not confirmation of the installed height or permission to build.

On sloping or uneven ground, seek advice before ordering. The fence layout and the relevant ground level need careful consideration.

4. How high can a garden fence be in England?

The figures below are the usual limits for a new fence without planning permission, not an absolute maximum height for every property.

• Beside a highway used by vehicles, including the pavement alongside it: generally no more than 1 metre above ground level without planning permission.
• Elsewhere: generally no more than 2 metres above ground level without planning permission.

This is not simply a front-garden versus back-garden rule. The fence’s relationship to the highway matters. Do not assume a fence set back from the road automatically falls under the 2-metre limit; ask your local planning authority if the position is unclear.

A taller fence may be possible with planning permission. Listed buildings and their grounds, boundaries adjoining listed buildings, Article 4 directions and conditions on earlier planning permissions can also change what is allowed. Altering an existing fence that is already above the usual limits has separate provisions, so do not use these figures alone to decide what you can replace.

Check the rules for your property with your local planning authority before ordering, especially near roads, junctions or driveways, or where levels change. Keep sightlines in mind rather than treating the height figures as approval of a particular design. This section covers England; rules elsewhere in the UK can differ.

Sources: council guidance on fence heights and exceptions and England’s permitted development legislation for gates, fences and walls. Planning information checked November 2026.

5. Concrete or timber fence posts?

Concrete post (left) and timber post (right), shown for comparison rather than to scale.

Concrete posts

Concrete does not rot like timber, making it an option worth considering where reducing timber decay is a priority. Slotted concrete posts can accept compatible panels and gravel boards, allowing individual panels to be removed without unscrewing them from the posts, provided the installation and clearance allow it.

The trade-offs are weight, handling and appearance. Concrete posts are heavy and can chip or crack if mishandled. They still need suitable foundations and correct installation; being concrete does not make a post maintenance-free or immune to damage. Choose the correct intermediate, end or corner design for each position.

Timber posts

Timber posts give a more continuous timber appearance and are generally lighter to handle. Suitable brackets or fixings can be attached to them, making them useful for a range of timber fence designs.

Timber can decay, particularly around ground level, and can split or move as it weathers. Choose posts with a treatment specification suitable for their intended use, including ground contact where applicable. Follow the supplier’s instructions for cut ends and care. Do not assume that a green or brown colour alone confirms the treatment specification or a particular lifespan.

Choosing between them

For a natural-looking all-timber boundary, timber posts may suit your preference. For a compatible slotted-panel system without timber post decay, concrete may be the better fit. Compare the complete installed cost, handling requirements, site conditions and replacement options rather than the post price alone.

A post’s total length is not its finished height above ground. Part of a buried post must be secured below ground. Get the required depth, foundation details and post specification from the relevant manufacturer or a competent installer; there is no single depth suitable for every fence and ground condition.

For a single straight run of separate panels with no gates, corners or shared existing supports, the basic count is one more post than panels. More complex layouts need a position-by-position count.

Browse concrete and timber fence posts and check their individual details.

6. Choosing gravel boards: material and finish

A gravel board sits below the timber fencing, helping separate the panel or boards from direct ground contact. It is a separate component to include in your dimensions and materials list, not a reason to ignore drainage or installation details.

Concrete versus timber gravel boards

Concrete gravel boards do not rot like timber and can provide a durable base beneath compatible fencing. They are heavier to handle and less straightforward to alter on site. Check their length, thickness and fit with the chosen posts before ordering.

Timber gravel boards give a matching timber appearance and are generally lighter and easier to cut to suit a timber construction. They are exposed to moisture near ground level and may need replacing as they decay. Use timber specified for the intended conditions and follow treatment and fixing instructions.

These are general material comparisons, not a claim that every option is available in every size. Check our current range before making your list. Neither a standard gravel board nor a fence panel should be assumed suitable for retaining a bank of soil; that needs a separately designed solution.

Rock-faced versus plain-faced concrete gravel boards

Plain-faced (left) and rock-faced (right) concrete gravel boards.

Plain-faced boards have a relatively flat, undecorated face for a simple, understated finish. Rock-faced boards have a moulded, stone-effect texture for a more decorative base.

The visible finish is the main distinction, not proof that one is stronger or will last longer. Compare the actual board specification and dimensions. Check whether the decorative finish is on one or both sides and which way it will face, particularly along a shared boundary.

Our concrete range includes plain-faced and rock-faced options. A board intended for one construction system should not be assumed to fit another. Remember that the amount of gravel board above ground contributes to the finished fence height.

Do not forget the fixings

Add brackets, suitable fasteners and the specified post-setting materials to your list. Bolt-down post supports and drive-in spikes are different fixing options, not automatic substitutes for buried posts. Suitability depends on the fence, exposure, ground or base and the manufacturer’s installation requirements.

View fencing accessories once you have chosen the main components.

7. Postcrete / post mix: how much do you need?

Post mix, often referred to as “Postcrete”, is used to secure fence posts. Postcrete is a specific brand; we stock an alternative brand, so follow the coverage and application instructions on the product you buy. We use “post mix” throughout the advice below.

Is it two bags per post? Not automatically. Two 20kg bags per post can be used as a provisional shopping allowance, but the amount actually required depends on the specified hole width and depth, the size of the post and the chosen product’s yield. Some installations need less and others more. Do not make the hole smaller simply to fit a bag allowance.

Agree suitable hole dimensions for your fence and ground conditions first, then use the chosen manufacturer’s coverage guidance to calculate the bags needed. Check the actual bag weight and yield: different post mixes are not necessarily interchangeable bag for bag.

Follow the exact product instructions for water, adding the mix, support and loading time. Initial setting time is not the same as permission to load the fence fully. Wear the protective equipment specified on the bag and safety information.

8. A simple materials-count example

Imagine a straight run made from five complete panels, starting and ending with new posts. Assume no gates, corners, slopes or existing supports, and one compatible gravel board beneath each panel.

• 5 fence panels.
• 6 posts, with the correct end and intermediate types for the chosen system.
• 5 gravel boards.
• Fixings and post mix as specified for that system and site.

If you provisionally budget for two 20kg bags of post mix per post, six posts would mean 12 bags. This is an example shopping allowance only, not a verified requirement: replace it with the quantity calculated for your actual holes, posts and chosen mix before ordering.

This example demonstrates counting, not an exact overall run length. Five panels nominally 1.83m wide do not automatically make a fence exactly 9.15m long: post widths and the way panels fit into slots or brackets affect the complete layout. Work from the system’s installed dimensions before deciding how many bays fit your boundary.

Common mistakes to avoid

• Buying from nominal sizes without checking actual dimensions.
• Forgetting that gravel boards and trellis affect finished height.
• Assuming every front garden has the same planning limit.
• Mixing panels, boards and posts without checking compatibility.
• Counting panels but overlooking end posts, corners and gate openings.
• Ordering fixing materials before establishing ground conditions and the installation method.
• Assuming every post needs exactly two bags of mix.
• Choosing treatment by timber colour rather than its specification and intended use.

Your pre-order checklist

• Record each fence run, gate opening, corner and change in level.
• Confirm the proposed finished height and any planning requirements.
• Choose the panel style or closeboard system and check actual dimensions.
• Count the correct post types, gravel boards, rails and boards.
• Check timber treatment is suitable for each component’s intended use.
• Confirm compatible fixings and calculate post mix from the specified holes and product coverage.
• Arrange buried-service checks and a safe installation method before digging or driving spikes.
• Check stock availability and collection or local-delivery arrangements.

Planning a fencing project near Brownhills?

Bring your measurements, a sketch and a few photos to Grasmere Garden Centre, Lichfield Road, Brownhills, WS8 6LL. They are a useful starting point for discussing the products in our range. For site-specific structural or planning questions, speak to a competent installer or your local planning authority.

Our fencing range is available for collection or local delivery rather than nationwide shipping. Check product availability and fulfilment options before ordering or travelling.

Browse the full Grasmere fencing range and start putting together your materials list.