Most of us know Buzz Lightyear’s line “To infinity and beyond”. But does this apply to the airspace above our land or buildings?
This was the question posed to me by my friend Jim in the pub. Jim likes to think that one day he could make heaps of money from developing property. Jim has never owned any property but likes to imagine what he would do if he did. Lately, he has been thinking about the potential of rooftop extensions or building new flats on top of the roofs of buildings as well as new shops and living spaces in basement levels, particular in light of how affordable new space can be rather tight in many of our cities. Our conversation goes something along the lines of this:
If I own a property presumably I own the airspace above it and all the ground below it?
It’s not as straightforward as you think. The position is largely clearer in relation to freehold but more ambiguous for leaseholds.
In the case of Grigsby v Melville  1WLR 80 the court took the view that “in the absence of indications to the contrary a conveyance of land includes not only everything on the surface but everything beneath it down to the centre of the earth and the space directly above” ; and in Lord Bernstein vs Skyviews & General  QB 479 the court took the view that the ownership of freehold land normally includes such airspace above it “as is necessary for the ordinary use and enjoyment of the land and structures on it”.
Bocardo SA v Star Energy UK Onshore Ltd (2010) UKSC 35 contemplated the position in relation to the subsoil and the court there took the view that the ownership of the subsoil probably only extended down to “the point at which physical features such as pressure and temperatures render the concept the strata belonging to anybody so absurd as to be not worth arguing about”.
The more recent cases Rosebery Ltd vs Rocklee Limited EWHC B1 2947, Ralph Kline Ltd v Metropolitan and County Holdings Ltd  EWHC 64 (Ch) and Gorst v Knight  EWHC 613 (Ch) highlight that the position is not clear in relation to leaseholds and that there is no presumption that a lease including a roof will extend upwards to the full height of the airspace available to the freeholder.
So how will I know if I can build on top of a roof if it is a leasehold building or I own the top floor flat or if I can build a cool underground lair like the evil villains in the movies?
You’d have to look at the lease and check the full extent of the premises demised under the lease. Even if the airspace above the roof is demised, the lease might restrict or define the extent of the height of the airspace above the building which the demised premises forms part of. You’d also have to consider the factors surrounding the particular case and property which could rebut any presumptions.
Why do you always have to spoil my fun? Come on then Little Miss Miserable, what else do I need to think about?
The supporting structure of a building often does not part of leasehold premises of part of a building. You also need to consider possible rights of light, not overloading structures and foundations, rights of any third parties and easements running below, and rights of support and protection to other parts of the building. That just scratches the surface. So sadly Jim, it may not be “to infinity and beyond”.