Advertisement•Independent leasehold data and advisory service•Not a law firm or regulated financial institution
England & Wales only

Note on leasehold reform (June 2026): The Leasehold and Freehold Reform Act 2024 has received Royal Assent and abolishes marriage value. However, the valuation provisions have not yet commenced — secondary legislation is still pending. The existing 1993 Act framework, including marriage value for sub-80-year leases, remains the applicable law for current transactions. This calculator reflects the current statutory position. We recommend verifying with a solicitor or RICS surveyor before serving notice.

Statutory Leasehold Extension Calculator

Estimate the premium payable to your freeholder under the Leasehold Reform, Housing and Urban Development Act 1993. Secure your property's value before the 80-year Marriage Value threshold.

Independent mathematical estimation based on current statutory frameworks (1993 Act, Sportelli deferment rate 5%). This estimate is for guidance purposes only and does not constitute formal legal or valuation advice.

Premium Estimation Tool

Your flat's estimated open market value with an extended (999-year) lease. This is your base valuation figure.

£
Please enter your property's estimated value.

The unexpired term of your current lease. Below 80 years triggers mandatory Marriage Value.

Please enter the years remaining on your lease (1–999).

The current annual ground rent payable under your lease. Enter 0 if your ground rent is a peppercorn.

£
Please enter your annual ground rent (0 or greater).

Enter your details below to receive a PDF copy of this estimate — and to be connected with an RICS-regulated surveyor if you wish to proceed.

Please enter your name.
Please enter a valid email address.
Please enter a valid phone number.

A leasehold specialist may contact you to verify the data and discuss your options. There is no obligation to instruct any service.

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The 80-Year Rule Explained

Under the Leasehold Reform, Housing and Urban Development Act 1993, the cost of a statutory lease extension increases significantly once the remaining term falls below 80 years. At that point, you become liable for Marriage Value — an additional payment representing 50% of the uplift in your property's value created by the extension.

A flat worth £300,000 with 74 years remaining may require a Marriage Value payment of £20,000–£40,000 on top of the base premium. The same flat with 81 years remaining would pay nothing in Marriage Value. Time is a material cost factor.

The Leasehold and Freehold Reform Act 2024 will abolish Marriage Value, but this provision is not yet in force (see the notice at the top of this page). Serving a notice now, under the current 1993 Act framework, avoids any uncertainty over the pending reform's implementation timeline.

Data Processing

01

Input property metrics

Enter your current valuation, unexpired lease term, and ground rent schedule into the calculator above.

02

Algorithmic assessment

The tool calculates the core premium and, where applicable, the statutory Marriage Value element under current 1993 Act rates.

03

Detailed estimate report

Receive a full PDF breakdown by email, with a summary of the statutory components and guidance for negotiating with your freeholder.

Frequently Asked Questions

How accurate is this calculator?
This tool uses the standard statutory deferment rate of 5% (as established in Sportelli) and a simplified capitalization model consistent with the 1993 Act framework. It provides a reliable order-of-magnitude estimate. Actual premiums may vary depending on the specific relativity table applied, tribunal decisions, and any bespoke lease terms. Always commission a formal RICS valuation before serving a Section 42 notice.
What is Marriage Value and why does it matter?
Marriage Value is the increase in property value created when a leaseholder extends their lease. Under the 1993 Act, when fewer than 80 years remain, the freeholder is entitled to 50% of this uplift as part of the extension premium. It can add tens of thousands of pounds to the cost. It will be abolished under the LFRA 2024, but that provision is not yet in force — current transactions remain subject to Marriage Value.
Does extending my lease require a solicitor?
Yes. The statutory route under the 1993 Act involves formal legal notices (Section 42 notice, counter-notice) with strict time limits. Errors can be costly. You should instruct an SRA-regulated solicitor specialising in leasehold law. This calculator helps you understand the financial position before that conversation.
Is this connected to a specific law firm or surveyor?
Hicaustilto is an independent advisory and data platform. We are not a law firm. When you request the full PDF report, we may introduce you to RICS-regulated surveyors and SRA-regulated solicitors from our network. You are under no obligation to instruct any of them.
Does this apply in Scotland or Northern Ireland?
No. The 1993 Act and the LFRA 2024 apply to England and Wales only. Scotland operates a different tenure system (most flats are owned on a feuhold basis), and Northern Ireland has its own leasehold framework. This calculator should not be used for Scottish or Northern Irish properties.