Leasehold Reform Act 2024 update:
The Act abolishes marriage value and introduces 990-year extensions, but these provisions are not yet in force — they require secondary legislation still awaited. This calculator uses current law (1993 Act rules).
Lease Extension · England & Wales · 2025/26
How much will your lease extension cost?
Estimate the statutory premium you would pay to extend your lease, broken down into its three components — ground rent capitalisation, reversion value and marriage value.
80 yrsCritical threshold for marriage value
Your property details
Enter the details below for an estimated premium range. All figures are estimates — get a formal RICS valuation before serving any notices.
£
The current market value of your leasehold flat as it stands today.
yrs
Check your lease or Land Registry title. This is the most important input.
£
Your current annual ground rent. Enter 0 if peppercorn.
Check your lease for any ground rent review clauses.
%
Standard Sportelli rate is 5% for flats. Lower rates increase the premium.
%
Typically 6–8% depending on ground rent amount and lease terms.
%
The value of your lease as % of freehold value. Auto-estimated from lease length if left blank.
Location affects relativity values used in the calculation.
Estimated premium breakdown
Capitalised ground rentPresent value of ground rent income the freeholder loses
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Reversion valueCompensation for delaying the freeholder's reversion
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Marriage value Lease under 80 years50% of the value created by extending the lease (current law)
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Estimated statutory premiumIndicative range — actual premium subject to negotiation or tribunal
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Total budget estimate
Premium
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Your surveyor
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Your solicitor
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Total budget
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How the premium grows as your lease shortens
The premium increases as the lease shortens — with a sharp jump at the 80-year mark where marriage value becomes payable under current law.
Premium above 80 yearsPremium below 80 years (marriage value applies)
Estimated value added to flat
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Approximate increase in market value from extension
Net financial impact
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Value added minus total cost (rough estimate)
New lease term
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Under current 1993 Act rules (90-year extension)
How the Leasehold Reform Act 2024 affects this
This calculator provides indicative estimates only, based on the Leasehold Reform Housing and Urban Development Act 1993 using standard Sportelli rates and established relativity tables. Results should not be used to serve Section 42 Notices, in formal negotiations, at tribunal, or for any other legal purpose. Always instruct a RICS-accredited leasehold valuation surveyor for a formal opinion. Rates used: deferment 5%, capitalisation 6%.
Frequently asked questions
How is a lease extension premium calculated in the UK?
The premium consists of three parts: Capitalised Ground Rent (value of rent the landlord loses), Reversion Value (compensation for the landlord waiting longer to get the flat back), and Marriage Value (only applicable if the lease has less than 80 years remaining).
What is the 80-year rule for lease extensions?
If a lease has 80 years or more remaining, no marriage value is payable to the landlord. Once it drops below 80 years, the law requires you to pay the landlord 50% of the value added to the property by the extension, significantly increasing the cost.
Has marriage value been abolished by the 2024 Reform Act?
While the Leasehold and Freehold Reform Act 2024 legislates for the abolition of marriage value, these provisions have not yet been commenced into law. Current extensions still follow the 1993 Act rules, including marriage value for leases under 80 years.
How long does a lease extension take?
A statutory lease extension typically takes four to twelve months from serving the initial notice, depending on how quickly the landlord responds and whether the premium is agreed by negotiation or referred to tribunal.
Do I have to own my flat for a minimum period before extending the lease?
Previously you needed to have owned the flat for at least two years before serving a statutory notice, but this qualifying period has been removed, so new owners can now serve a notice as soon as they complete.
What happens if my landlord doesn't respond to my extension notice?
If the landlord fails to respond within two months, you can apply to the county court for a vesting order, which grants the extension on the terms you proposed.