The short answer
You can build a fence right up to your boundary line, provided the entire structure, including the posts and any concrete footings, sits on your own land. There is no rule forcing a fence to be set back from the boundary. What you cannot do is build over the line onto your neighbour's land, or place footings that encroach, as that is trespass. Because the exact legal line is rarely marked precisely and title plans show only general boundaries, many people deliberately set the fence a few centimetres inside their own boundary to be sure they are not encroaching. The height limits (2 metres, or 1 metre next to a road) apply wherever you site it.
This question is really two questions: where the law lets you put the fence, and where it is wise to put it. The answer to the first is 'anywhere on your own land up to the line'; the answer to the second often involves a small, deliberate margin.
Fence position at a glance
- On the boundary lineAllowed, if wholly on your land
- Over the lineTrespass — not allowed
- FootingsMust also stay on your land
- Set back inside your landCommon, to avoid encroachment
- Height limitsApply wherever you site it
You can build up to the line, on your own land
There is no legal requirement to leave a gap between your fence and the boundary. You are entitled to erect a fence as close to the boundary as you like, even directly on the line, as long as the whole structure sits on your own land. That includes the visible panels and posts and, crucially, anything below ground: post holes, concrete footings and spurs must all be within your property.
This is why a fence right on the boundary is perfectly normal and lawful. The constraint is not distance from the line but ownership of the land the fence occupies. If every part of the fence is on your side, you can build as close to the boundary as you wish.
Building over the line is trespass
The line you cannot cross is, literally, the boundary line. If any part of your fence, above or below ground, sits on your neighbour's land, that is an encroachment and amounts to trespass. Common ways this happens by accident include:
- Footings spreading across the line: a concrete footing wider than the post can extend onto the neighbour's land even if the visible post is on yours.
- Building on the existing fence's footprint when that fence was itself slightly over the line.
- Assuming a feature marks the boundary when the true line is elsewhere.
A neighbour whose land is encroached upon can require you to remove the offending part. Even a small encroachment can sour relations and, in a dispute, become expensive to resolve, so the safe principle is to keep everything demonstrably on your side.
| Where the fence sits | Allowed? |
|---|---|
| Wholly on your land, on the line | Yes |
| A few centimetres inside your land | Yes — common, safest |
| Posts on your land, footings over the line | No — encroachment |
| Panels overhanging the line | No — trespass |
| On a shared (H-mark) boundary | By agreement with co-owner |
Lawful and unlawful fence positions relative to the boundary. Source: general property law; HM Land Registry boundaries guidance.
Why title plans do not pinpoint the line
A key practical reality is that you usually cannot know the exact boundary line to the centimetre. HM Land Registry title plans show general boundaries only: they indicate the broad position, not a surveyed line precise enough to settle a few centimetres either way. The red edging on a title plan is not a precise legal definition of where your land stops.
This is why disputes about whether a fence is 'on the line' are often unanswerable from the plan alone. Establishing the precise legal boundary requires examining the original conveyance, the physical evidence on the ground, and sometimes a chartered surveyor or a formal determined boundary application to the Land Registry. Because of this uncertainty, building a fence exactly on the supposed line carries a real risk of accidental encroachment.
Why a small set-back is often the smart choice
Given that the exact line is uncertain, many people deliberately set their fence a small distance inside their own boundary. The advantages are:
- No risk of encroachment: if the fence and all its footings are clearly on your side, you cannot be accused of trespass even if the true line turns out to be slightly different from where you thought.
- Access to both sides: a fence set just inside lets you maintain and treat both faces from your own land, without stepping onto the neighbour's property.
- Avoiding disputes: a visible margin makes it obvious the fence is yours and on your land.
The trade-off is that you give up a small strip of usable garden, and the land between the fence and the true boundary remains yours but sits behind the fence. For most people the certainty is worth more than the few centimetres lost. If you do set back, it is sensible to make clear (ideally in writing to the neighbour) that the fence does not mark the legal boundary, so the set-back is not later mistaken for ceding land.
Practical steps before you build
To position a fence cleanly:
- Check ownership and T-marks on your title plan so you know whether the boundary is yours to fence.
- Identify the line as best you can from the original conveyance and physical evidence, accepting that the plan shows only general boundaries.
- Keep all of the fence on your land, including footings, or set it slightly inside to be safe.
- Talk to your neighbour first, especially if the existing fence is shared or if you are replacing one near the line.
- Respect the height limits: 2 metres generally, 1 metre next to a road, measured from the higher ground level.
Where the line genuinely matters and the neighbour disagrees, a determined-boundary application or surveyor's advice is the formal route, but for most fences a careful set-back and a friendly conversation prevent any difficulty.
Frequently asked questions
Can I put my fence right on the boundary line?
Yes, as long as the entire fence, including posts and footings, sits on your own land. There is no rule forcing a set-back. The risk is that the exact line is rarely certain, so building right on it can lead to accidental encroachment. Many people set the fence a few centimetres inside their boundary to be safe.
Do I have to set my fence back from the boundary?
No. You can build up to the line, but only on your own land. A small set-back is a common choice because it removes any risk of encroaching on the neighbour and lets you maintain both sides from your own garden. If you set back, make clear the fence does not mark the legal boundary.
What happens if my fence footings cross onto my neighbour's land?
That is an encroachment and amounts to trespass, even if the visible posts are on your side. Your neighbour can require you to remove the offending part. Concrete footings can spread wider than the post, so keep them clearly within your land or set the fence slightly inside the boundary.
Sources & further reading
- HM Land Registry — practice guide 40: boundaries (general boundaries)
- GOV.UK — disagreements about property boundaries
- Planning Portal — fences, gates and garden walls
Figures on this page are typical UK ranges drawn from published sources and depend on your specific garden. They are guidance, not a quotation.