The legal principle cuius est solum eius est usque ad coelum et ad inferos ('whoever owns the soil, owns up to heaven and down to hell') has been significantly qualified in modern law. While a landlord does own the airspace above their land, that ownership is limited — aircraft can overfly at reasonable heights without trespass, and the practical extent of airspace ownership is the height necessary for the ordinary use and enjoyment of the land and the structures on it (Bernstein of Leigh v Skyviews and General Ltd [1978] QB 479). However, within the effective zone of ownership, airspace rights have real commercial value — particularly for rooftop telecoms equipment, external advertising hoardings, oversailing crane licences, and rooftop development rights.
The Bernstein Principle — How Much Airspace Do You Own?
The foundational English authority on airspace rights is Bernstein of Leigh v Skyviews and General Ltd [1978] QB 479. In that case, a landowner sued an aerial photography company for trespass to airspace when aircraft flew over his property to take photographs. Griffiths J held that an owner's right to airspace extends only to such height as is necessary for the ordinary use and enjoyment of the land and the structures on it — above that height, the owner has no greater rights than any member of the public. The court was concerned that unlimited airspace ownership would expose aircraft and satellite operations to a multitude of trespass claims. The practical implication for landlords is that ordinary use of the building (roof, chimneys, antennae, plant equipment, advertising on the building exterior) is within the zone of ownership; aircraft or drones flying at normal operational heights above the building are not trespassing.
- Bernstein v Skyviews [1978]: landowner's airspace rights extend to the height necessary for ordinary use and enjoyment — not to unlimited altitude
- Above that height: no greater rights than any member of the public — aircraft, commercial drones at operational altitudes, and satellites are not trespassing
- Below that height: within the zone of ordinary use — structures, plant equipment, antennae, rooftop installations, external advertising are all within the landlord's airspace rights
- Civil Aviation Act 1982 s.76: aircraft flying at a height that is reasonable in the circumstances and complying with Air Navigation Orders cannot be sued for trespass to airspace
- Practical zone: for most buildings, the relevant airspace zone extends from ground level to the top of the roof plus a reasonable margin for plant and services
Telecoms Equipment and the Electronic Communications Code
The growth of mobile data networks has made rooftop space for telecoms equipment one of the most valuable commercial uses of airspace. The Electronic Communications Code (Schedule 3A of the Communications Act 2003, as inserted by the Digital Economy Act 2017) gives code operators (mobile network operators and other authorised telecoms providers) significant rights to install and maintain electronic communications apparatus on, under, or over land. Under paragraph 3 of the Code, no code right can be acquired without either the landowner's agreement or a court order. The 'no scheme' valuation principle (paragraph 24) means that consideration for a code agreement is assessed without reference to the fact that the land is suitable for telecoms use — significantly reducing what operators pay compared to the pre-2017 regime. The Product Security and Telecommunications Infrastructure Act 2022 (PSTI 2022) further enhanced code rights for upgrades and equipment sharing.
- Electronic Communications Code (Sch 3A CA 2003): code operators can install telecoms apparatus on/under/over land — by agreement or court order
- 'No scheme' valuation (Code para 24): consideration assessed without the fact that land is suitable for telecoms — significantly lower rents than pre-2017; confirmed in Cornerstone v Compton Beauchamp [2022] UKSC 18
- Agreement vs court order: operators try to agree; if landowner refuses unreasonably, operator applies to Upper Tribunal (Lands Chamber) for a code agreement
- PSTI 2022: enhanced upgrade and sharing rights for existing code operators — landlords have less ability to refuse upgrades to existing installations
- Negotiate carefully: once a code agreement is in place, the 'no scheme' valuation and PSTI 2022 rights limit the landlord's ability to increase rent — negotiate initial terms carefully
Oversailing Cranes — Trespass to Airspace
Where a construction project requires cranes that swing over a neighbouring property's airspace, this constitutes trespass to airspace if done without the neighbour's consent — even where the jib is above the roofline and nothing physically touches the neighbouring property (Anchor Brewhouse Developments v Berkley House (Docklands Developments) Ltd [1987] 2 EGLR 173). The neighbour landowner has the right to seek an injunction to prevent the crane from oversailing, or to negotiate a licence fee — sometimes called an 'oversailing licence'. Commercially, the licence fee varies depending on the extent and duration of the oversailing. Where a landlord of a commercial or residential building is approached by a neighbouring developer for an oversailing licence, this is a valuable opportunity to negotiate payment — and the developer may have strong incentive to pay rather than face injunctive relief that could halt construction.
- Anchor Brewhouse [1987]: crane jib oversailing neighbouring property's airspace is a trespass — even if nothing physically touches the property or comes close to the roofline
- Injunction: landowner is entitled to an injunction to prevent ongoing trespass — threat of injunction is strong leverage in licence fee negotiations
- Oversailing licence: negotiate a fee for granting consent to oversail — typically based on the duration; extent of oversailing; and any risk of physical interference
- Commercial leverage: developer with planning permission and imminent construction needs the licence — the landlord is in a strong position to negotiate
- Licence terms: specify duration; insurance by the crane operator; indemnity for any physical damage to the neighbouring property; access for inspection if required
Advertising Hoardings and External Signage
Airspace above the landlord's building — the external walls, roof, and parapet — can be licenced for advertising hoardings and external signage. This generates passive income without affecting the building's use. Planning permission is required for most advertisements (Advertisement Regulations 2007 — Town and Country Planning (Control of Advertisements) (England) Regulations 2007); deemed consent applies only to small-scale signs (Category A and B in the Regulations). Where the building is in a Conservation Area or is Listed, additional restrictions apply. The landlord who grants an advertising licence must also comply with any covenants in their own leasehold or freehold title that restrict the use of the exterior for advertising purposes — check the title before entering into advertising agreements.
- Planning permission: most advertising hoardings and large signs require planning consent under the Advertisement Regulations 2007 — deemed consent only for Category A/B (small, low-key signs)
- Conservation Area and Listed Buildings: further restrictions apply; listed building consent needed where external changes affect the character of a listed building
- Licence income: advertising licences on prominent buildings (particularly in high footfall urban locations) can generate significant passive income — typically annual payments based on footfall and visibility
- Title covenants: check the freehold or superior leasehold title for restrictions on external advertising before granting advertising licences
- Scotland/Wales: Advertisement Regulations apply in Scotland and Wales with minor modifications; planning consent requirements broadly similar
Rooftop Development and Airspace Development Rights
The Town and Country Planning Act 1990 and its Permitted Development Rights (PDR) regime include provisions for certain upward extensions — adding additional storeys to existing buildings. The Town and Country Planning (General Permitted Development) (England) Order 2015 (as amended) has been extended in recent years to allow additional storeys on certain residential and commercial buildings without planning permission, subject to conditions and prior approval. For landlords with commercial buildings, permitted development rights to add additional residential floors are potentially highly valuable. Any development of rooftop space — whether for PV panels, plant equipment, telecoms, or structural additions — requires assessment of planning requirements, building regulations, structural adequacy of the existing building, and any restrictions in the title or superior lease.
- Permitted development rights: GPDO 2015 (as amended) includes rights for additional storeys on some residential and commercial buildings — prior approval from LPA required; conditions apply
- Airspace development: commercial building-owner can potentially add residential upper floors using PDR — generating significant value from previously unused airspace
- Planning assessment: some rooftop works fall outside PDR and require full planning permission — always check planning status before beginning work
- Building regulations: any structural addition to existing buildings requires Building Regulations compliance — structural engineer assessment of existing building's load-bearing capacity essential
- Title restrictions: check the landlord's own title and any superior lease for restrictions on alterations to or development of the roof — many commercial leases require superior landlord consent
Frequently asked questions
How high does a landlord's airspace ownership extend?+
Under Bernstein v Skyviews [1978], a landowner's airspace rights extend to the height necessary for the ordinary use and enjoyment of the land and structures on it — not to unlimited altitude. Aircraft and commercial drones at operational heights above the building are not trespassing (Civil Aviation Act 1982 s.76). Within the zone of ordinary use, the landlord has full property rights.
Is a crane oversailing my property a trespass?+
Yes — Anchor Brewhouse Developments v Berkley House [1987] confirmed that a crane jib swinging over a neighbouring property's airspace is a trespass even if nothing physically touches the building. The landowner can seek an injunction or negotiate an oversailing licence fee. The threat of injunction gives the landowner significant leverage in licence fee negotiations.
What rights do telecoms operators have to install equipment on my roof?+
Code operators (mobile network operators) have rights under the Electronic Communications Code (Sch 3A Communications Act 2003) to install apparatus on land — by agreement or, if agreement is refused, by court order from the Upper Tribunal. Compensation is assessed on a 'no scheme' valuation basis (Code para 24), giving operators significant leverage on price. Negotiate initial terms carefully — they are difficult to improve once a code agreement is in place.
Do I need planning permission for advertising hoardings on my building?+
Usually yes — most advertising hoardings and signs require planning consent under the Advertisement Regulations 2007. Deemed consent applies only to small-scale Category A and B signs. Additional restrictions apply in Conservation Areas and for Listed Buildings. Always check planning requirements before entering into advertising licence agreements.
Can I develop additional floors on top of my commercial building?+
Permitted Development Rights (GPDO 2015 as amended) allow additional storeys on some buildings — subject to conditions and prior approval from the Local Planning Authority. The scope of PDR for upward extensions has been extended in recent years. Always confirm planning status with the LPA before relying on PDR — the conditions and restrictions are complex and site-specific.