QUESTION: There are some old mine workings near our house that have been sealed up for years. The local records office has plans that show at least one tunnel under our garden, a long way below the surface. Precisely how far down does our property go or do we own everything underneath the house?

ANSWER: There is an ancient principle of Roman law that “cuius est solum eius est usque ad coelum et ad inferos” (“for whoever owns the soil, it is theirs up to the sky and down to the depths”). This rule has been applied in England and Wales for many centuries. A Court of Appeal judge said in 1913 that it was quite clear that when someone bought land “it includes the surface and all that is supra - houses, trees, and the like ... and all that is infra - mines, earth, clay, etc.” According to this principle, any burrowing far beneath your house would be a trespass.

There are two ways in which rights to the land underneath the house can change. First, the owner of the surface of the land may grant permanent or temporary permission to go under the land. For example, many mine workings were dug out in accordance with long mineral leases granted to Victorian mining companies. Permission can also take the form of a wayleave - an agreement (typically with a telephone or a utility business) to run pipes and cables under private land. Second, legislation sometimes allows enterprises to compulsorily acquire rights to dig under private land. For example, a phone company that cannot negotiate a wayleave can apply to the court under the Telecommunications Act 1984 to force an unwilling owner to accept phone lines under its land.

In the era of space travel and deep tunnelling, lawyers have started to test the legal limits of this ownership. In the recent case of Star Energy v Bocardo, one Court of Appeal judge stated that the Latin principle above illustrated the basic law in England and Wales - although the references to the “sky” and the “depth” were simply “hyperbolic”. He said that if landowners really did own everything right down to the centre of the Earth we would all end up with a lot of neighbours. The court decided that the owner of a large house in Surrey plainly owned rock layers 2,800ft below ground and that an oil company had technically trespassed by drilling at that depth. Unfortunately it decided not to explore how much deeper the landowner's rights extended.

The short answer to your question is therefore that you certainly own the land to at least 2,800ft down, but law has yet to go any deeper than this.

The writer is a barrister at Tanfield Chambers. E-mail your questions to: brief.encounter@thetimes.co.uk

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