The Stokes v Cambridge (1961) Valuation Principle
In UK land development, a 'ransom strip' is a small parcel of land (often only inches wide) situated between a development site and the public adopted highway. Without legal vehicular access over this strip, the backland parcel is effectively landlocked and cannot be developed.
In Stokes v Cambridge Corporation (1961) 180 EG 839, the Lands Tribunal determined how such strips should be valued. The court ruled that the ransom owner is entitled to a fair proportion—customarily one-third (33.33%)—of the net increase in site value created by granting the access easement.
Calculating the Net Development Value Uplift
The valuation begins with a residual development appraisal. First, the valuer calculates the Gross Development Value (GDV) of the completed scheme with planning permission. Second, all development deductions are subtracted: construction costs, site preparation, professional fees, planning obligations (CIL and S106), financing costs, Existing Use Value (EUV) of the raw land, and a market developer profit margin (typically 15% to 20% of GDV).
The residual amount represents the 'Net Development Uplift'. In a standard sole-access scenario, the ransom strip buyout is calculated as 33.33% of this net uplift. In Batchelor v Kent County Council (1989) 60 P&CR 518, the Court of Appeal confirmed that the hypothetical willing buyer and willing seller negotiation assumes neither party acts unreasonably, capping ransom valuations below 50%.
Overcoming Ransom Strips: Prescription Act 1832 & Easements of Necessity
Developers should always conduct historical diligence before negotiating a ransom buyout. Under Section 2 of the Prescription Act 1832 and the common law doctrine of lost modern grant, if vehicular access has been enjoyed openly and continuously for 20 or more uninterrupted years without permission or payment ('nec vi, nec clam, nec precario'), a legal easement by prescription is established.
The developer can register this prescriptive right at HM Land Registry using Form ADV1 and a Statement of Truth (Form ST4). Once registered, the access is permanent, defeating the ransom strip and reducing its commercial value to £0.