'We think our neighbour might change our boundaries – how can we stop them?'

Dear Property Doctors,

In the summer of last year, our neighbours sought planning permission for a single storey extension to the side of their corner property. Various other nearby residents were notified by the council of the plans and were invited to raise any objections to them prior to approval. 

However, despite ours being the only adjacent property with a boundary that abuts the proposed extension, we were not notified. We only became aware in March this year that the plans not only existed but had been approved. 

The council claims that a vagary in the numbering of the houses here led them to assume we had no interest in the matter. Clearly, they had not looked at the ground plan of the existing buildings.

Having obtained copies of the approved plans from the local planning office website, it became clear to us that the plans show the boundary between the two properties following a straight line. It is in fact curved at one end. 

Current Land Registry documents and the original deeds of our house clearly show this curve. We raised this with our neighbour, who was dismissive as the extension itself will not encroach onto our property. We also raised this with the planning department, who have not responded to us. 

We are concerned that, having granted planning permission on the basis of incorrect plans, the council have opened up the possibility of future boundary disputes when either house is later sold on. Do we need or have any remedy here?

AC, by email

It is unfortunate that you did not receive notice of the planning application, but this does not invalidate the planning permission.

Even if you had been notified and objected, I suspect planning permission would still have been granted. It is important to understand that the planners are not concerned about boundary issues. They can only decide whether permission should be granted on planning grounds – ie. that the proposed development will not be too intrusive and so on.

You should make it clear to your neighbour that you do not accept that the boundary is where the plans submitted to the council show it to be. Ideally, you should show him where you say the boundary is.

If possible, try and get him to enter into an agreement with as detailed a plan as possible showing the correct boundary. That agreement can be filed against both titles at the Land Registry so as to avoid problems arising in the future.

If you cannot agree where the boundary is, then the only way the matter can be resolved is by litigation. These boundary disputes are invariably very expensive. Litigation should always be the last resort and this maxim applies with particular force to these sorts of cases.

If you do notify your neighbour about where you say the boundary is, then he ought to inform any buyer of this. If the neighbour is selling, it would be sensible to let your neighbour’s solicitors and estate agents know the problem. They would then be under a duty to inform any prospective purchasers.

David Fleming is the head of property litigation at William Heath & Co solicitors (williamheath.co.uk)