FREEHOLD OWNERSHIP OF
AIRSPACE AND SUBSOIL
The questions of who owns the air above our heads and the earth beneath our feet affects modern life in many ways. It may impact on a basement development under an expensive house in Holland Park, fracking in Lancashire, a landlord’s wish to add a new floor on top of a block of flats or a hobbyist’s desire to fly a drone over his neighbour’s back garden. Modern statutes will be relevant to many of the issues that arise in this context but the starting point remains the common law and its treatment of the vertical extent of landownership.
Legal legend has it that the owner of land owns everything above it up to the sky and below it down to the centre of the earth or, to put it theologically, up to heaven and down to hell. The origin of that legend is a Latin maxim, cuius est solum eius est usque ad coelum et ad inferos (or some version of it), which has been attributed to Accursius, a commentator on Roman law who lived in Bologna in the 13th century. A form of the maxim is to be found in English law reports as early as the 16th century, in Bury v Pope (1586) Croke, Elizabeth 118. It was discussed by Lord Coke in ‘On Littleton’ published in 1628 and has cropped up in law reports and text books regularly ever since.
The maxim is an oversimplification as legal maxims tend to be, but not without force even today. In Bocardo SA v Star Energy UK Onshore Ltd  UKSC 35 Lord Hope, with whom the rest of the Court agreed, held that, “the brocard1 still has value in English law as encapsulating, in simple language, a proposition of law which has commanded general acceptance”.
Bocardo is the leading authority on freehold ownership of subsoil. In that case Star Energy had a government issued licence to search for oil in a reservoir of petroleum and natural gas beneath land in Surrey. Star Energy’s predecessor had bored under Bocardo’s land and laid pipelines between 800 feet and 2,800 feet beneath the surface without Bocardo’s consent. The licence permitted the extraction of the gas and petroleum below the surface (which belonged to the Crown by statute) but if Bocardo owned the strata down to that depth, the licence did not authorise the laying of pipes in the strata which would therefore be a trespass. Star Energy argued that Bocardo’s ownership of the land did not extend down to the depths at which the pipelines had been installed. That argument was rejected. Lord Walker distinguished between subsoil and airspace (as to the latter see below). So far as subsoil is concerned, he held that:
“…the owner of the surface is the owner of the strata beneath it, including the minerals that are to be found there, unless there has been an alienation of it by a conveyance, at common law or by statute to someone else… There must obviously be some stopping point, as one reaches the point at which physical features such as pressure and temperature render the concept of the strata belonging to anybody so absurd as to be not worth arguing about.”
The pipelines, however, were “far from being so deep as to reach the point of absurdity” and hence were a trespass into Bocardo’s land.
While the Supreme Court recognised in Bocardo that there was a depth below which it could not be meaningfully said that a landowner’s ownership extends, it can be seen that this depth is so far below the surface that it is difficult to conceive of anyone laying claim to the strata below it. In practice, therefore, freeholders do own the soil below the surface “ad inferos”, i.e. as far down as could have any conceivable practical use.
To that general statement there will be exceptions where the subsoil or minerals within it belong to someone else as a result of a conveyance, statute or the common law. As far as mines and minerals go, all gold and silver in mines vests in the Crown by common law (specifically by Royal Prerogative); see Attorney-General v Morgan  1 Ch 432. Petroleum in its natural condition in strata vests in the Crown by s. 2 of the Petroleum Act 1998 (consolidating earlier legislation). Unworked coal and coal mines are vested in the Coal Authority by s. 7 of the Coal Industry Act 1994 (having previously been vested in the British Coal Corporation and before that the National Coal Board and before that the Coal Commission, the previous iterations of what is now the Coal Authority).
The invention of manned flight created obvious difficulties with the application of the cuius est solum eius est usque ad coelum maxim to an indefinitely high column of airspace. Two hundred years ago, in Pickering v Rudd (1815) 4 Campbell 219, Lord Ellenborough LCJ was to be found discussing whether the maxim would render “an aeronaut … liable to an action of trespass …, at the suit of the occupier of every field over which his balloon passes in the course of his voyage”. He thought not.
Statutes such as the Air Navigation Act 1920 and the Civil Aviation Act 1982 provided protection from actions in trespass or nuisance by reason of aircraft flight over property at a reasonable height above the ground but did not attempt to refine the common law as to the vertical extent of land ownership. That has been left to the courts. In Bernstein of Leigh v Skyviews & General  QB 479 Griffiths J observed that to apply the maxim literally would lead to the absurdity that it would be a trespass for a satellite to pass over a suburban garden. He held that the balance between a landowner’s right to enjoy his land and the general public’s rights to use airspace was:
“.. best struck … by restricting the rights of an owner in the air space above his land to such height as is necessary for the ordinary use and enjoyment of his land and the structures upon it, and declaring that above that height he has no greater rights in the air space than any other member of the public”.
Bernstein has been cited approvingly in various subsequent cases, including in the Supreme Court in Bocardo, and must be taken to be a correct statement of the law. In Bernstein itself it was held that the defendant did not trespass on Lord Bernstein’s property by flying over it to take aerial photographs.
On the other hand, there has been held to be a trespass or nuisance where:
a cornice overhung a neighbour’s garden: Fay v Prentice (1845) 1 CB 828
an advertising sign projected over a neighbour’s property: Gifford v Dent  WN 336 and Kelsen v Imperial Tobacco Co (of Great Britain and Ireland) Ltd  2 QB 334
an extractor fan projected over the claimant’s yard: Laiqat v Majid  EWHC 1305 (QB).
An unauthorised trespass into a neighbour’s airspace will normally be restrained by injunction. See Trenberth (John) Ltd v National Westminster Bank Ltd (1979) 39 P & CR 104.
4. Statutory Regulation of Flight Through Airspace
As indicated above, it has long been recognised that landowners’ rights to the airspace above their land cannot be allowed to inhibit the use of that airspace, above a reasonable height, for powered flight. Aviation in the United Kingdom is regulated by the Civil Aviation Act 1982, the Airports Act 1986, the Transport Act 2000, the Civil Aviation Act 2012 and various statutory instruments including the Air Navigation Order 2016 and the Rules of the Air Regulations 2015. There is also much European Union law which affects United Kingdom air law (at least for the time being). This book is not the place for a detailed discussion of aviation law. Reference should be made to specialist texts for a full discussion of the UK and EU statutory regimes affecting flight and the international agreements to which much of the legislation gives effect.
5. Dealings with freehold interests in airspace or subsoil
As will be discussed further in subsequent chapters, there is nothing to prevent the freehold owner of land carving out a horizonal division of it to sell, be that above or below the ground. The Law of Property Act 1925, s. 205(1)(ix) provides that ‘“Land” includes land of any tenure, and mines and minerals, whether or not held apart from the surface, buildings or parts of buildings (whether the division is horizontal, vertical or made in any other way) …’.
A freehold interest in an upper storey of a building is known as a “flying freehold”. According to Lord Keith in Sovmots Investments Ltd v Secretary of State for the Environment  AC 144 at 184:
“Horizontally divided ownership of a building was extremely uncommon in England and Wales in 1957, being practically unknown… outside Lincoln’s Inn. It is a conception which gives rise to a very complicated situation as regards the mutual rights and obligations of the several owners. It is, however, a conception familiar to the law of Scotland for centuries …”.
Flying freeholds are not so uncommon now, although they are still comparatively rare.
Indeed, a flying freehold is capable of being acquired by adverse possession. See, for example, Abbahall Ltd v Smee  1 WLR 1472.
Even where the flying freehold is created by a conveyance or transfer there can be difficulties in regulating responsibility for maintenance and support. Positive covenants are not enforceable against subsequent owners; see Rhone v Stephens,  2 AC 310, a case concerning the roof of a house divided into flying freeholds. The principle of benefit and burden (a subsequent owner enjoying a benefit may be made subject to a reciprocal burden) will sometimes enable a positive covenant to be enforced by or against the owner of a flying freehold, but not always. The House of Lords decided that it did not assist the plaintiffs in Rhone who were seeking to enforce a covenant to repair the roof.
Absent any enforceable covenant, a common law duty in nuisance to take reasonable steps to prevent injury to a neighbour may require the owner of a flying freehold to contribute towards the cost of repair works; see Abbahall Ltd v Smee  1 WLR 1472.
Flying freeholds do not only exist above ground level, as the name suggests. There can also be a subterranean flying freehold where, for example, a cellar is conveyed or reserved separately to the house above it; see Grigsby v Melville  1 WLR 80 at 83. The existence of a subterranean flying freehold beneath a building may cause conveyancing difficulties for the building above if there are not clear rights of support in favour of the building and protection in respect of the subterranean layer.
Whether a particular parcel of land, or horizontal division of a parcel of land, is included in a conveyance is a mixed question of fact and law. In Pennock v Hodgson  EWCA Civ 873 Mummery L.J. summarised the approach that the court takes to identifying boundaries as follows:
“(1) The construction process starts with the conveyance which contains the parcels clause describing the relevant land, in this case the conveyance to the Defendant being first in time.
(2) An attached plan stated to be “for the purposes of identification” does not define precise or exact boundaries. An attached plan based upon the Ordnance Survey, though usually very accurate, will not fix precise private boundaries nor will it always show every physical feature of the land.
(3) Precise boundaries must be established by other evidence. That includes inferences from evidence of relevant physical features of the land existing and known at the time of the conveyance.
(4) In principle there is no reason for preferring a line drawn on a plan based on the Ordnance Survey as evidence of the boundary to other relevant evidence that may lead the court to reject the plan as evidence of the boundary.”
Normally, the plan to a conveyance will only show the outline of the land being sold at ground level, rendering it of little use if a question arises as to whether the parcel conveyed includes a subterranean level or a particular area above ground. The words of the parcels clause (the clause describing what is being conveyed) may make the position clear but, if not, the Court’s starting position is likely to be as follows:
A conveyance of land ordinarily carries with it all that is beneath the surface (Grigsby v Melville  1 WLR 80 at 85 and 88, where a cellar was conveyed with the property above it even though the most convenient access was from a neighbouring property).
Since ownership of land normally carries with it the airspace above the land to such height as is necessary for the ordinary use and enjoyment of the land, a conveyance of land normally carries with it the whole of any building standing on it. In Laybourn v Gridley  2 Ch 53, for example, where part of a loft projected into the neighbouring property, it was held that the projecting part of the loft was conveyed as part of the neighbouring property.
Where the footings or eaves of a building extend beyond the boundary shown on a plan to a transfer separating the two parcels, the usual inference will be that they were intended to be included. Hence the transferee may acquire the footings and eaves but not the column of air between them. See Truckell v Stock  1 WLR 161.
A question that does not appear to have featured in many cases is whether a flying freehold comprising part of a building carries with it the airspace above or subsoil below the building. Consider a 3 storey building owned by A. A sells the freehold of the top floor including the roof to B, or of the ground floor to C, in either case retaining the other two floors. Does B acquire the airspace above the building or C the subsoil beneath it? Or do they remain with A who retains two-thirds of the building? Or are they somehow shared? The question would have to be approached by construing the conveyance to B or C. What, objectively speaking, were the intentions of the parties as to the vertical extent of the interest conveyed? Hence the question is essentially one of the boundary of the flying freehold sold, rendering it unlikely that A and B or C, as the case may be, would be held to share ownership of the subsoil or airspace unless the transfer expressly provides for joint ownership. If the terms of the transfer considered with the physical features of the land do not throw any light on the parties’ intentions, the cuius est solum eius est usque ad coelum et ad inferos maxim may raise an inference that the subsoil was to go with freehold ownership of the bottom floor or airspace with freehold ownership of the top floor.
That is by no means the only possible inference, though. In Corbett v Hill (1869-70) LR 9 Eq 671 Sir William James V-C considered exactly this issue. C owned two adjoining houses and sold one of them to H. During redevelopment works by H it became apparent that a first-floor room retained by C projected into the house sold to H and was supported by it. Both parties claimed the air space above that room. The Vice-Chancellor held that H owned the air space. C retained the room (as a flying freehold) but owned nothing above or below it. The room was a diminution of H’s ownership of the land and house that H had purchased, which otherwise extended upwards on the cuius est solum eius est usque ad coelum principle. Unfortunately, the judgment does not provide much explanation for why the Judge reached his conclusion. Nevertheless, in Laybourn v Gridley  2 Ch 53 (discussed in Chapter 3) North J said that he would have applied the decision in Corbett regarding the airspace above part of a loft alleged to comprise a flying freehold had he found the loft to be a flying freehold rather than within the ownership of the building beneath the loft.
In relation to subsoil, the fact that the whole building’s foundations will be within the subsoil may point away from an inference that the subsoil goes with a flying freehold of the ground floor, as it has been held to do in the case of a lease of the ground floor (dealt with in the following chapter).
If the land in question is an adopted highway, the surface of the highway (which will include the footpath as well as the carriageway) will vest in the highway authority. The subsoil beneath the highway will continue to vest in the owner of the land, though. So, at common law the owner of the land containing the highway may tunnel under it and extract minerals provided that he does not remove support for the highway or interfere with apparatus laid under it by statutory undertakers (pipes, sewers, etc.); see e.g. Cunliffe v Whalley (1851) 13 Beav 411.
Similarly, the owner of the land containing the highway owns the air above it and can erect, for example, wire above it so long as they do not interfere with the right of passage over the highway; see Finchley Electric Light Co v Finchley UDC  1 Ch 437.
That said, ss. 176 to 179 of the Highways Act 1980 prevents the owner of the subsoil from creating cellars and vaults under a highway or erecting bridges, buildings, rails and beams over it without the consent of the highway authority.
1A term meaning Latin legal maxim