Fences, gates and walls: the 1 metre limit beside a highway

One metre beside a road, two metres everywhere else. That is the whole of the fence height permitted development highway rule in Part 2 Class A of the GPDO 2015, and the arguments are never about the numbers. They are about what counts as being beside a road, where ground level starts, and whether the trellis you added on top is part of the fence.

The pavement is the trap. A footway is part of the highway, so a front fence standing behind the pavement of an ordinary residential street is adjacent to a highway used by vehicular traffic, and the limit is 1 metre. Not 2 metres, even though no car ever comes within three metres of it.

The 1 metre and 2 metre height limits

Class A of Part 2 permits the erection, construction, maintenance, improvement or alteration of a gate, fence, wall or other means of enclosure. The limits are:

• 1 metre above ground level where the enclosure is adjacent to a highway used by vehicular traffic.
• 2 metres above ground level in every other position.
• For work to an existing enclosure, the greater of its former height and the height that would have been permitted had it been built new. So a lawfully existing 1.8 metre front wall can be repaired and rebuilt to 1.8 metres, but not raised.

That third limb is the one that saves most front boundaries. Older front walls were often built well above a metre before the rules applied, and rebuilding to the same height stays within the class.

The right is removed within the curtilage of a listed building and where the enclosure would bound a listed building, and it can be removed by an Article 4 direction. In a conservation area the height limits are unchanged, which surprises people, though taking an existing wall down raises a separate question dealt with below.

What counts as adjacent to a highway

A highway is not just the carriageway. It includes the footway and usually the verge, and the extent of the public highway is recorded on the highway authority's definitive records, not on your title plan.

So the test is whether the boundary fronts a highway that vehicles use, taking the whole width of that highway into account. A front garden boundary on a residential street is caught. A side boundary running along the same street is caught for its whole length. A rear boundary onto a service road is caught. A rear boundary onto a public footpath with no vehicular use is not, and 2 metres applies there.

Two frequent misreadings:

A private driveway shared with neighbours is not a highway unless it has become one by dedication, and a shared drive subject to rights of way remains private land. The 2 metre limit normally applies.

Being set back does not help. There is no stated distance at which a boundary stops being adjacent to the highway, and an officer will treat a fence running parallel to the street along the front of the plot as adjacent even if a verge sits in between.

If the position is unclear, ask the highway authority for the extent of the highway in writing before you build. It costs nothing and it settles the point.

Measuring height on sloping ground

Height is taken from ground level. Where ground levels differ on either side of the enclosure, the measurement is from the higher side, which is why so many rear boundary fences on sloping plots are unlawful without anybody realising.

The sequence that catches people is the one where a neighbour's garden is a metre higher. A 2 metre fence measured from your own lawn is 1 metre above their ground, which is fine. Build the same fence from their side and it is 3 metres above yours, which is not.

Where the ground itself has been raised, the comparison is against the original level rather than the new one. Importing soil to create a terrace and then putting a 2 metre fence on the new surface produces an enclosure measured from the pre-existing ground.

Gate posts, pier caps and finials count. A 2 metre fence with 2.2 metre posts is a 2.2 metre means of enclosure.

The same measuring convention runs through the rest of Part 1 and Part 2, which is why the arithmetic in the 50 per cent curtilage rule for garden outbuildings uses the original curtilage rather than the plot as it stands today.

Listed buildings and curtilage walls

Class A does not apply within the curtilage of a listed building or to a boundary of one, so any gate, fence or wall there needs planning permission.

Separately, where a boundary wall is itself listed, either in its own right or as a curtilage structure predating 1 July 1948 and within the curtilage at the date of listing, works to it need listed building consent. That applies to repair involving alteration, to repointing in a different mortar, to taking a section out for a new opening, and to removal.

Listed building consent and planning permission are different consents with different tests, and a scheme may need both. Where harm to significance is in issue, a Heritage Statement setting out the significance of the wall and the effect of the works is what the conservation officer will look for.

Repointing a listed garden wall in cement rather than lime is the most common unauthorised work of this kind, and it is the hardest to reverse.

Conservation areas and Article 4 directions

Inside a conservation area the Class A height limits are the same as anywhere else. What changes is demolition.

Taking down a boundary wall in a conservation area can require planning permission for relevant demolition where the wall exceeds 1 metre in height and abuts a highway or public open space, or exceeds 2 metres elsewhere. Councils treat that seriously because the loss of front boundary walls is one of the main ways the character of a Victorian or Georgian street is eroded. Ask the council before removing anything.

An Article 4 direction can remove Part 2 Class A outright, usually in a conservation area or a designed estate. Check the council's list of directions for your road, since directions are street-specific and the council's constraints map will show them.

The same checking discipline applies to front gardens generally. The hard surfacing rules in front garden paving, permeable surfaces and Class F interact with boundary work, because a new driveway and a new front wall are usually done together and one of them may need permission while the other does not.

Retaining walls and engineering operations

A wall that holds back ground is doing something different from a wall that encloses land, and the distinction matters.

Where the structure retains a change in level it may be an engineering operation rather than a means of enclosure, and engineering operations within a residential curtilage are not permitted by Class A. Where a wall both retains and encloses, the pragmatic approach most authorities take is to measure the whole structure from the lower ground level and apply the Class A limits to the total.

A retaining structure on a boundary also engages your neighbour's rights. Excavation within 3 metres of an adjoining owner's structure, or within 6 metres where the excavation cuts a line of 45 degrees from their foundations, brings the Party Wall etc. Act 1996 into play, and that runs on its own notice periods regardless of planning.

Get a structural design for anything retaining more than about half a metre. It is the one part of boundary work that fails expensively.

Trellis, planting and screening on top of a fence

Trellis counts. The height of a fence includes any trellis fixed to it, so the familiar arrangement of a 1.8 metre fence with 300 millimetres of trellis above is a 2.1 metre means of enclosure and outside the class.

Planting does not count, because growing a hedge is not development and there is no planning height limit on one. There is a separate remedy: under Part 8 of the Anti-social Behaviour Act 2003 a neighbour can complain to the council about an evergreen or semi-evergreen hedge over 2 metres that acts as a barrier to light or access, and the council can issue a remedial notice requiring it to be reduced.

Climbing plants on a lawful fence are fine. A row of containerised bamboo in 1.5 metre planters on top of a 2 metre wall will be read as an alteration to the means of enclosure, whatever the catalogue called it.

Where you need more than the class allows, a householder planning application is the route, and a short Planning Statement addressing street character, visibility at the access and the effect on neighbours is usually enough for a boundary case. And if you need certainty that something already built is lawful, a Lawful Development Certificate under section 191 or 192 of the Town and Country Planning Act 1990 is the only formal way to establish it.

This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it.

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