Walls, fences and gates adjoining a highway
Boundary enclosures are permitted development up to one metre next to a vehicular highway and two metres elsewhere. Here is how the limits are measured, what alterations are allowed and where the class falls away.
The fence height next to highway permitted development limit is one metre, and two metres everywhere else. Part 2 Class A of Schedule 2 to the Town and Country Planning (General Permitted Development) (England) Order 2015 permits the erection, construction, maintenance, improvement or alteration of a gate, fence, wall or other means of enclosure, subject to those two heights, a rule about raising an existing structure, and a flat exclusion for anything within the curtilage of a listed building or on the boundary of that curtilage.
The one metre and two metre limits
The one metre limit applies where the enclosure is adjacent to a highway used by vehicular traffic. The two metre limit applies to everything else, which in a normal plot means the side and rear boundaries.
Both figures are measured above ground level and both are absolute. A 2 m fence with a 100 mm gravel board under it is 2.1 m and outside the class. A 1 m front wall with a 150 mm coping on top is 1.15 m and outside it too, which is why so many front boundary disputes are about coping stones.
A hedge is not caught at all. Planting is not development, so there is no height limit on a hedge under planning law, though the high hedges provisions in the Anti-social Behaviour Act 2003 give neighbours a separate complaint route for evergreen hedges over 2 m. Trellis on top of a fence does count towards the height, because it forms part of the means of enclosure.
What adjacent to a highway means
A highway used by vehicular traffic includes the carriageway and the footway and verge that form part of that highway. So a front boundary facing a pavement is adjacent to a highway used by vehicular traffic even though no car ever touches the pavement.
Two situations cause genuine uncertainty.
A public footpath that carries no vehicles is a highway, but not one used by vehicular traffic, so the two metre limit applies to a boundary facing it. Check the definitive map rather than assuming, because many urban alleys are vehicular highways on paper.
And "adjacent" has no statutory distance. A wall set back several metres behind the footway, with a front garden between, may still be treated as adjacent. There is no safe measurement to rely on, so where a front enclosure is planned above one metre and set back, ask the authority in writing or apply for a certificate.
Measuring height on sloping ground
Heights are measured above ground level, and where the ground differs from one side to the other, the practice councils apply is to measure from the higher ground.
That produces results people find counterintuitive. A 1.8 m close-boarded fence on the high side of a 600 mm level difference is 1.8 m from the higher garden and 2.4 m from the lower one. Measured from the higher side it is within the two metre limit, which is the usual reading. Reverse the slope and the same fence fails.
On a sloping street frontage, each panel is assessed where it stands rather than as an average across the run. A stepped wall that rises to 1.3 m at the low end of the plot has a section outside Class A even if the mean height is under a metre. Draw it as a proper elevation against existing ground levels rather than describing it in a sentence.
Altering or improving an existing wall
Class A covers maintenance, improvement and alteration as well as new work, with an important qualification. The altered structure must not end up higher than its former height, or higher than the limit that would apply if it were being built new, whichever of those two is greater.
So an existing 1.6 m front wall, lawfully there, can be repaired, rebuilt or re-rendered at 1.6 m. It cannot be raised to 1.8 m, because that exceeds both its former height and the one metre new-build limit. A 600 mm front wall can be raised to one metre, because the new-build figure is the greater of the two.
Three practical points.
The former height has to be the lawful former height, which for a structure altered without permission in the past is not necessarily what is standing today.
Replacing a wall entirely is construction rather than alteration if nothing of the original remains, but the same ceiling applies either way, so the distinction rarely matters.
Keep dated photographs and a measured drawing of the existing structure before work starts. In any later dispute about what the former height was, that file is the whole case.
Listed buildings and conservation areas
Class A does not apply to development within the curtilage of a listed building, or to a boundary of the curtilage of a listed building. That is a complete exclusion, not a reduced height, so a new 900 mm garden wall at a listed cottage needs planning permission, and works to a wall that is itself part of the listing need listed building consent as well.
Conservation areas are different and widely misunderstood. Part 2 Class A is not restricted on the land described in Article 2(3) of the Order, so the one metre and two metre limits apply in a conservation area just as elsewhere. Two cautions though.
An Article 4 direction can remove Class A locally, and front boundary treatments are a common target for such directions in areas with a consistent historic frontage.
Demolition of a boundary wall in a conservation area can need planning permission in its own right, because a substantial wall may be a building and its removal relevant demolition. Taking a Victorian front wall out to make a parking space is the scenario that catches people, and it usually arrives alongside the paving question covered in the note on permeable surfaces and Class F.
Gates, access and visibility
A gate within the one metre limit is permitted. The access it opens onto is a separate question.
Part 2 Class B permits the formation of a means of access to a highway that is not a trunk road or classified road, but only where the access is required in connection with development permitted by another class in Schedule 2. A new dropped kerb serving an existing house is therefore not covered, and forming a vehicular access onto a classified road needs planning permission whatever its width.
Separately, the physical crossing of the footway requires the highway authority's consent under section 184 of the Highways Act 1980, and that is a different application to a different team with its own fee and specification. Visibility splays, gradient, gate opening direction and the depth available to stand a car clear of the footway are all highway matters, and a gate that opens outwards over a public footway will be refused.
Electric gates bring a further point. The gate motor, pillars and intercom all count towards the height of the means of enclosure.
Retaining walls are different
A structure whose purpose is to hold back ground is an engineering operation rather than a means of enclosure, so Part 2 Class A is not the right place to look. Where a wall both retains and encloses, authorities take different views, and the pragmatic reading is that the retaining function governs.
That matters because there is no one metre or two metre allowance for an engineering operation in a garden. A 1.2 m retaining wall across a front garden to form a level parking area is development needing permission, and the application will attract questions about surface water, the stability of the highway and tree roots. The curtilage arithmetic in the 50 per cent rule for garden outbuildings is a reminder that these classes are read for what they say rather than what seems reasonable.
Confirming the position in writing
For anything marginal, the only binding confirmation is a certificate of lawfulness of proposed use or development under section 192 of the Town and Country Planning Act 1990, or section 191 for work already done. A certificate is the only formal way to confirm that works are lawful.
Where an application is needed, it is usually a householder application with a site plan, an elevation against existing ground levels, a section where levels change, and a short Planning Statement dealing with the street scene, visibility and any heritage effect. Front boundary applications turn on the character of the frontage far more than on the height itself, so photographs of neighbouring walls along the street carry weight.
Illustrative example: a 1930s semi with a 500 mm front wall and a 1.8 m side fence between it and the pavement of a side road. Rebuilding the front wall at one metre is permitted. The side fence faces a vehicular highway, so it is limited to one metre too, and the existing 1.8 m fence can only be maintained at its lawful former height rather than replaced taller. A planning application for 1.8 m on the side boundary succeeds on the strength of five comparable fences photographed along the same road.
This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval. To see what a householder application usually contains, browse the report types on PlanScope.
Frequently asked questions
How high can a fence be next to a road?
One metre above ground level where it is adjacent to a highway used by vehicular traffic, which includes the footway and verge forming part of that highway. Two metres applies to other boundaries. Both figures include gravel boards, copings and trellis, because those form part of the means of enclosure.
How is fence height measured on sloping ground?
Above ground level, and where levels differ on either side the practice authorities apply is to measure from the higher ground. Each section is assessed where it stands rather than averaged along the run, so a stepped wall rising at the low end of a plot can have one section outside the class.
Can I raise an existing boundary wall?
Only to the greater of its lawful former height or the height that would be permitted for a new structure in that position. So a 600 millimetre front wall can go to one metre, but a 1.6 metre front wall cannot be raised at all, because 1.6 exceeds both its former height and the one metre new-build limit.
Do fence rules change in a conservation area?
The one and two metre limits are the same, because Part 2 Class A is not restricted on Article 2(3) land. Two things do change in practice: an Article 4 direction may have removed the right locally, and demolishing a substantial boundary wall can need permission as relevant demolition in a conservation area.
Does a new driveway gate need permission?
The gate itself is permitted within the height limits, but the access is separate. Part 2 Class B does not cover a new access serving an existing house, and an access onto a classified road always needs permission. The footway crossing also needs the highway authority's consent under section 184 of the Highways Act 1980.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.