How much does a short lease devalue a property? More than most sellers expect — and the damage accelerates as the lease shrinks. If you own or are buying a leasehold flat, the number of years left on the lease is one of the biggest single influences on its value and its mortgageability.
The typical discounts
As a rule of thumb, a lease above 90–100 years has little effect on value. Between 80 and 90 years, discounts of roughly 5–10% appear. Below 80 years — the critical threshold — the discount deepens to 10–20%, and below 60 years a flat can lose a third or more of its freehold-equivalent value. Many lenders simply refuse to mortgage leases under ≈70 years, which shrinks your buyer pool to cash purchasers and pushes the price down further.
Why 80 years is the cliff edge
Once a lease falls below 80 years, extending it becomes significantly more expensive because “marriage value” — the uplift created by the extension — enters the premium calculation. That is why solicitors urge leaseholders to act before the 80-year mark, and why buyers should check the lease length before offering, not after.
What it means if you’re buying the freehold instead
For leasehold houses, buying the freehold (enfranchisement) follows a similar valuation logic — the shorter the lease, the higher the premium. Our lease extension FAQ covers the mechanics and timescales.
Getting the number right
Online calculators give a range, not a defensible figure. A RICS lease extension valuation establishes both the current impact on your property’s value and the premium you should expect to pay — essential before you negotiate with the freeholder or serve a Section 42 notice. It is also the figure a tribunal will take seriously if negotiations fail.
Speak to a surveyor before it becomes a dispute
Kingston Surveyors arranges RICS party wall surveyors, building surveys and valuations across London and the surrounding counties. If you are unsure where you stand, call us on 0204 579 8270 or request a call back and we will organise the right professional for your situation — usually with an appointment within days.
