Adam Keith by

Posted on January 18, 2017

As the recent trend for developing basements continues, legal issues can arise where the owner of the land under which the basement is built is unknown. This commonly occurs when an existing basement sits underneath the public highway. Often the true owner of the land is unknown, although it is likely to belong to the local authority.  Ad medium filum can be rebutted and adverse possession is of limited use because the local authority that likely owns the land will be able to defeat the claim.

There are several options available to deal with this issue:

  1. Contact the council and request they transfer this portion of the land/grant a long lease
  2. Try to claim adverse possession of the area
  3. Do nothing and rely on ad medium filum if someone comes forward

All three options are fraught with dangers and risks which could make the issue worse. Option 3 is likely to be rejected by any lender involved in the transaction.

An Insurance Solution

Another option is to insure the land against claims from the owner. This can be a cost effective solution which lenders will accept. It can also be put in place extremely quickly. Insurers will want to know:

  1. The length of occupation (estimated)
  2. Whether there has been an contact with any parties likely to own the land
  3. Whether there have been any disputed
  4. The value of the land

It should be noted that some insurers will exclude claims from the local authority and highways agency. This is likely to render the policy useless in most cases involving the public highway.


Another similar issue is when a building overhangs the public highway. An oversail licence will likely be in place, but often the permission of the freeholder is not obtained. This may be because they are unknown, or it was not obtained from the council at the same time as the licence. This can become an issue for purchasers and lenders who may feel a valuable aspect of the property is at risk. Developers can also face issues where cranes oversail areas of unknown ownership. Insurance can provide a cost effective solution to dealing with the risk of a freeholder requesting the area be removed, or development ceased.

If you would like to discuss any of the content covered in this blog post please contact:

Adam Keith, Transactional Liability Manager
[email protected]
0203 058 2536