The Marriage-Value Margin: Appraising Short-Lease Flats as Development Stock in 2026
Photo: Douglas, James, Public domain, via Wikimedia Commons
Short leases are often discussed as a binary defect: either the flat is financeable or it is not. For developers, that framing is too crude. The unexpired term is a variable that can be quantified, priced and, in many cases, cured. The more serious risks usually sit elsewhere: a freeholder who will not engage, ground-rent records that cannot be reconciled, or a title that cannot support a clean statutory claim.
The 80-year line is a pricing hinge, not a cliff
Under the statutory lease-extension regime, the marriage value enters the valuation once the unexpired term falls below 80 years. That does not make a flat unsaleable. It changes the method by which the premium is calculated. Above the line, the freeholder is generally compensated for ground rent and reversion. Below it, the freeholder may also share in the value created by the extension itself.
The practical consequence is that a 79-year lease is not simply a 78-year lease with one fewer year of value. It is a different negotiation. A developer who buys at 82 years and sells at 78 years has crossed the threshold without any physical change to the building. The discount should reflect that, and the exit buyer’s lender criteria should be checked before exchange, not after refurbishment.
Statutory qualification also matters. The leaseholder normally needs to have owned the flat for two years before serving a claim, and the lease must be a long lease at the outset. A buyer who completes without the seller having already served a valid notice may need to wait before making a statutory claim. That wait is not a legal technicality; it is a holding cost and a financing cost.
What the premium is made of
A lease-extension premium is not a single number pulled from a calculator. It is built from the capitalised ground rent, the freeholder’s reversion, and, where the lease is short enough, 50% of the marriage value. The leaseholder also pays the freeholder’s reasonable legal and valuation costs, subject to the statutory framework and any tribunal assessment.
The premium is negotiable. The statutory process provides for a notice, a counter-notice and a period of negotiation. If agreement cannot be reached, the matter can go to the tribunal. That route is slower and more expensive, but it is also a discipline on unrealistic freeholder demands. The developer’s appraisal should carry a realistic premium and a realistic timetable, not the best-case figure from an initial enquiry.
A worked appraisal
The following illustrative example shows how the discount, the premium and the post-extension exit interact on a typical UK do-er-upper purchase. The figures are simplified for illustration and are not a substitute for a formal valuation.
| Item | Amount |
|---|---|
| Purchase price, 72-year lease, unmodernised | £210,000 |
| Refurbishment | £40,000 |
| Lease-extension premium | £35,000 |
| Statutory and own professional costs | £5,000 |
| Total cost | £290,000 |
| Exit value, refurbished with 90-year extension | £340,000 |
| Gross margin | £50,000 |
| Margin on cost | 17.2% |
The premium in this example is derived from an assumed post-refurbishment value of £285,000 with the existing 72-year lease and £340,000 with a 90-year extension at a peppercorn ground rent. The freeholder’s existing interest is assumed at £15,000. Marriage value is therefore £40,000, of which 50% is £20,000. Add the freeholder’s interest and the premium is £35,000 before costs.
The purchase price reflects a £130,000 gap to the post-refurbishment extended value, but that gap is not profit. It must fund the refurbishment, the premium, the professional costs and the holding period. If the claim takes nine months rather than six, finance and site costs will absorb part of the margin. The developer should underwrite the timetable as well as the price.
The timetable is part of the price
A statutory lease-extension claim is not a conveyancing formality. A realistic planning assumption is six to twelve months from valid notice to completion, and longer where the freeholder is unresponsive or the case goes to tribunal. Where the two-year ownership rule applies, the wait before notice can add further months.
That timetable has three consequences. First, it ties up capital. Second, it exposes the project to changes in the market and in lending criteria. Third, it can force a sale with the short lease still in place if the developer runs out of time. A short-lease purchase should therefore carry a contingency for delay, not merely a contingency for the premium.
Due diligence that actually moves the needle
The unexpired term is visible on the title. The risks that cause projects to fail are less visible. The first is freeholder identity and solvency. The notice must be served on the correct party, and a dormant company, an absent landlord or a disputed appointment can stall the claim. Companies House filings and the registered title should be checked early.
The second is ground-rent records. Missing demands, unexplained arrears and informal receipts can complicate the premium calculation and the statutory process. A deed of variation may be needed to correct a defective ground-rent clause, and that is a separate negotiation with its own timetable.
The third is defective title. A missing lease plan, an absent landlord, an unregistered rentcharge or a lease that does not properly grant the flat can all undermine the claim. These are not reasons to walk away automatically, but they are reasons to price the remedy and to take specialist advice before exchange. Building safety information and any cladding remediation obligations should also be checked, because they affect the exit buyer’s lender and the service-charge forecast.
Reform: what changed and what to verify
The Leasehold and Freehold Reform Act 2024 signalled a significant shift in leasehold policy, including longer extensions, peppercorn ground rent and the removal of marriage value. On paper, that reduces the policy risk of a punitive extension premium. In practice, the operative question for a 2026 acquisition is commencement and transitional application. A developer should not capitalise reform into a bid until the commencement position and the tribunal’s approach are confirmed for the transaction in question.
Reform has genuinely changed the risk profile of short-lease flats by making the statutory route more attractive and politically more stable. It has not eliminated freeholder delay, poor records or defective title. Those are transaction risks, and they remain the developer’s responsibility.
The short lease is a line item, not a red flag
The better approach is to treat the unexpired term as a line in the appraisal: discount on purchase, premium to cure, costs to administer, time to complete, and exit value after extension. Where those numbers work, a short lease can be defensible development stock. Where they do not, the problem is usually not the 80-year line itself. It is the freeholder who cannot prove title, the ground rent that cannot be reconciled, or the lease that cannot support a clean claim.
