Horizontal Title Stratification: Modifying the Roman Law Maxim
Ancient English land law applied the Latin maxim 'cujus est solum, ejus est usque ad coelum et ad inferos' (whoever owns the soil owns everything up to the heavens and down to the depths of the earth).
However, modern English real estate jurisprudence recognized that freehold ownership can be severed horizontally into separate volumetric strata.
When a flying freehold is created:
1. Ground Stratum: The ground-floor owner holds a freehold title extending upwards to the underside of the first-floor joists.
2. Flying Stratum: The upper owner holds an independent freehold title over the airspace volume occupied by the upper room.
3. The Party Floor: The floor structure connecting the two volumes is legally treated as a party structure (analogous to a party wall).
| Building Component | Freehold Ownership Allocation | Legal Status | Restrictions on Use |
|---|---|---|---|
| Subsoil & Foundations | Ground-Floor Freeholder | Sole Freehold Title | Must not undermine structural integrity |
| Ground Floor Living Space | Ground-Floor Freeholder | Sole Freehold Title | Must not remove load-bearing internal walls |
| Party Floor Joists & Timbers | Shared Horizontal Boundary (Median line) | Party Structure | Neither owner may sever or weaken joists |
| Upper Overhanging Room | Flying Freeholder | Sole Freehold Title | Must not impose excessive dynamic structural loads |
| Roof & Chimney Stack | Upper Freeholder (or shared) | Dependent on roofline | Duty not to allow water ingress into lower levels |
Party Wall etc. Act 1996 Application to Party Floors
Under Section 2 of the Party Wall etc. Act 1996, the term 'party structure' explicitly includes a party floor or other horizontal partition separating buildings or parts of buildings with separate ownership.
If either neighbour intends to carry out structural works to the floor joists or insert steel beams (RSJs), they must serve a formal Party Structure Notice at least two months before commencing work.